diff --git a/python/llm/src/ipex_llm/transformers/lookup.py b/python/llm/src/ipex_llm/transformers/lookup.py
new file mode 100644
index 00000000..f26b26e9
--- /dev/null
+++ b/python/llm/src/ipex_llm/transformers/lookup.py
@@ -0,0 +1,319 @@
+#
+# Copyright 2016 The BigDL Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Some parts of this file is adapted from
+# https://github.com/huggingface/transformers/blob/main/src/transformers/generation
+# /candidate_generator.py and
+# https://github.com/huggingface/transformers/blob/main/src/transformers/generation
+# /utils.py
+#
+
+from typing import Callable, List, Optional, Tuple
+import torch
+import time
+import copy
+import logging
+from transformers import GenerationConfig, LogitsProcessorList, StoppingCriteriaList
+from ipex_llm.transformers.speculative import greedy, deepmind_sample, logits_to_probs,\
+    _crop_past_key_values, _prepare_generate_args, _non_cpu_ipex_verify, clear_benchmarks
+from ipex_llm.utils.common import invalidInputError
+
+logger = logging.getLogger("ipex_llm.lookup")
+
+# patch GenerationMixin.generate
+from transformers import GenerationMixin
+original_generate = GenerationMixin.generate
+query_group_size = 16
+
+
+@torch.no_grad()
+def generate(
+    self,
+    inputs: Optional[torch.Tensor] = None,
+    generation_config: Optional[GenerationConfig] = None,
+    logits_processor: Optional[LogitsProcessorList] = None,
+    stopping_criteria: Optional[StoppingCriteriaList] = None,
+    prefix_allowed_tokens_fn: Optional[Callable[[int, torch.Tensor], List[int]]]=None,
+    synced_gpus: Optional[bool] = None,
+    assistant_model: Optional["PreTrainedModel"] = None,
+    streamer: Optional["BaseStreamer"] = None,
+    **kwargs,
+):
+    lookahead = kwargs.pop("lookahead", None)
+    if lookahead:
+        from ipex_llm.transformers.convert import get_enable_ipex
+        _enable_ipex = get_enable_ipex()
+
+        if self.device.type == "cpu" and _enable_ipex:
+
+            logger.warning("Prompt lookup is currently not supported on CPU with IPEX, "
+                           "fallback to original generate.")
+            kwargs.pop("max_matching_ngram_size")
+        else:
+            # Do prompt lookup generation
+            return self.lookup_generate(inputs=inputs,
+                                        num_output_tokens=lookahead,
+                                        generation_config=generation_config,
+                                        logits_processor=logits_processor,
+                                        stopping_criteria=stopping_criteria,
+                                        prefix_allowed_tokens_fn=prefix_allowed_tokens_fn,
+                                        **kwargs)
+
+    return original_generate(self,
+                             inputs=inputs,
+                             generation_config=generation_config,
+                             logits_processor=logits_processor,
+                             stopping_criteria=stopping_criteria,
+                             prefix_allowed_tokens_fn=prefix_allowed_tokens_fn,
+                             synced_gpus=synced_gpus,
+                             assistant_model=assistant_model,
+                             streamer=streamer,
+                             **kwargs)
+
+GenerationMixin.generate = generate
+
+
+# This class is copied from https://github.com/huggingface/transformers/blob/main/src
+# /transformers/generation/candidate_generator.py
+class PromptLookupCandidateGenerator():
+    """
+    `CandidateGenerator` class to be used for prompt lookup generation.
+    This class generates candidates
+    by looking up
+    likely continuations in the provided prompt (input_ids) itself.
+    Read the following blog post for more information:
+    https://github.com/apoorvumang/prompt-lookup-decoding
+
+    Args:
+        max_matching_ngram_size (`int`):
+            The maximum ngram size to be considered for matching in the prompt
+        num_output_tokens (`int`):
+            The number of tokens to be output as candidate tokens.
+    """
+
+    def __init__(
+        self,
+        num_output_tokens: int = 10,
+        max_matching_ngram_size: int = None,
+    ):
+        self.num_output_tokens = num_output_tokens
+        self.max_matching_ngram_size = max_matching_ngram_size if max_matching_ngram_size else 2
+
+        invalidInputError(self.max_matching_ngram_size > 0 and self.num_output_tokens > 0,
+                          "Invalid max_matching_ngram_size or num_output_tokens")
+
+    def get_candidates(self,
+                       input_ids: torch.LongTensor)-> Tuple[torch.LongTensor,
+                                                            Optional[torch.FloatTensor]]:
+        """
+        Fetches the candidates to be tried for the current input.
+
+        Args:
+            input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
+                Indices of input sequence tokens in the vocabulary.
+                [What are input IDs?](../glossary#input-ids)
+
+        Return:
+            `torch.LongTensor` of shape `(num_candidates, candidate_length)`:
+            The candidate sequences to be tried.
+        """
+        input_length = input_ids.size(1)
+
+        chosen_ids = None
+        match_found = False
+        for ngram_size in range(min(self.max_matching_ngram_size, input_length - 1), 0, -1):
+            # Create sliding windows of size ngram_size
+            windows = input_ids.unfold(dimension=1, size=ngram_size, step=1)
+
+            # Convert ngram to a tensor for comparison
+            ngram_tensor = input_ids[0, -ngram_size:]
+
+            # Find where the windows match the ngram
+            matches = (windows == ngram_tensor).all(dim=2)
+
+            # Get the indices of matches
+            match_indices = matches.nonzero(as_tuple=True)[1]
+
+            # Iterate through match indices to find a valid continuation
+            for idx in match_indices:
+                start_idx = idx + ngram_size
+                end_idx = start_idx + self.num_output_tokens
+                end_idx = min(end_idx, input_length)
+
+                if start_idx < end_idx:
+                    chosen_ids = input_ids[0, start_idx:end_idx]
+                    match_found = True
+                    break
+            if match_found:
+                break
+
+        if chosen_ids is None or len(chosen_ids) == 0:
+            # In case we didn't find a match return the input sequence unchanged,
+            # reverts back to autoregressive decoding
+            return input_ids, None
+
+        # Now need extend input_ids with chosen_ids
+        chosen_ids = chosen_ids.unsqueeze(0)
+        candidate_input_ids = torch.cat((input_ids, chosen_ids), dim=1)
+        # assisted_generation expects logits as well, but we don't have those here,
+        # so returning None
+        return candidate_input_ids, None
+
+    def update_candidate_strategy(self, input_ids: torch.LongTensor,
+                                  scores: torch.FloatTensor, num_matches: int):
+        """
+        Updates the candidate generation strategy based on the outcomes.
+
+        Args:
+            input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
+                Indices of input sequence tokens in the vocabulary.
+                [What are input IDs?](../glossary#input-ids)
+            scores (`torch.FloatTensor` of shape `(batch_size, candidate_length,
+                config.vocab_size)`):
+                Prediction scores of a language modeling head. These can be logits for each
+                vocabulary when not using beam search or log softmax for each vocabulary
+                token when using beam search
+            num_matches (`int`):
+                The number of matches between the candidate sequences and the model predictions.
+        """
+        # Currently does nothing
+        return
+
+
+@torch.no_grad()
+def lookup_generate(self,
+                    inputs: Optional[torch.Tensor] = None,
+                    max_new_tokens: int = 10,
+                    num_output_tokens: int = 10,
+                    max_matching_ngram_size: int = None,
+                    generation_config: Optional[GenerationConfig] = None,
+                    attention_mask=None,
+                    **sampling_kwargs):
+    input_ids, generation_config, logits_processor, stopping_criteria, \
+        model_kwargs = _prepare_generate_args(self, inputs, generation_config,
+                                              **sampling_kwargs)
+
+    candidates_generator = PromptLookupCandidateGenerator(
+        num_output_tokens=num_output_tokens,
+        max_matching_ngram_size=max_matching_ngram_size)
+
+    step = 0
+    step_verify = 0
+
+    clear_benchmarks(self)
+
+    past_key_values = None
+    input_len = input_ids.shape[1]
+
+    while True:
+        if step >= max_new_tokens:
+            break
+
+        if step == 0:
+            # first token use full model
+            tic = time.time()
+            output = self(input_ids=input_ids,
+                          past_key_values=past_key_values,
+                          attention_mask=attention_mask,
+                          return_dict=True,
+                          use_cache=True)
+            logits = output['logits']
+            logits = logits[:, -1:]
+            logits[:, -1, :] = logits_processor(input_ids, logits[:, -1, :])
+            if generation_config.do_sample:
+                output_ids, prob_list = deepmind_sample(logits,
+                                                        top_k=generation_config.top_k,
+                                                        top_p=generation_config.top_p,
+                                                        temperature=generation_config.temperature)
+            else:
+                output_ids = greedy(logits)
+            input_ids = torch.cat((input_ids, output_ids), dim=-1)
+            past_key_values = output['past_key_values']
+            step += 1
+            if self.device.type == 'xpu':
+                torch.xpu.synchronize()
+            toc = time.time()
+            self.first_token_time = toc - tic
+            e2e_tic = time.time()
+        else:
+            cur_len = input_ids.shape[-1]
+            toc = time.time()
+            candidate_input_ids, _ = candidates_generator.get_candidates(input_ids=input_ids)
+            candidate_length = candidate_input_ids.shape[1] - input_ids.shape[1]
+            verify_input_ids = candidate_input_ids[:, -candidate_length - 1:]
+            self.draft_num.append(candidate_length)
+            tic = time.time()
+            self.draft_time.append(tic - toc)
+            output = _non_cpu_ipex_verify(self, verify_input_ids, past_key_values,
+                                          attention_mask, return_dict=True, use_cache=True)
+            if isinstance(output, dict):
+                logits = output['logits']
+                past_key_values = output['past_key_values']
+
+            if len(logits_processor) > 0:
+                for i in range(candidate_length + 1):
+                    logits[:, i, :] = logits_processor(candidate_input_ids[:, : cur_len + i],
+                                                       logits[:, i, :])
+
+            if generation_config.do_sample:
+                output_ids, prob_list = deepmind_sample(logits,
+                                                        top_k=generation_config.top_k,
+                                                        top_p=generation_config.top_p,
+                                                        temperature=generation_config.temperature)
+            else:
+                output_ids = greedy(logits)
+
+            if self.device.type == 'xpu':
+                torch.xpu.synchronize()
+            toc = time.time()
+            self.verify_time.append(toc - tic)
+
+            # Compare drafts with target verified outputs
+            # Drafts start from [1, k]
+            # Verified output start from [0, k - 1]
+            # including the one generated by the base model
+            max_matched = ((output_ids[:, :-1] != verify_input_ids[:, 1:]).cumsum(-1) == 0)
+            max_matched = max_matched.sum(-1).item() + 1
+
+            max_of_max_matched = output_ids.size(1)
+            # Accept number is max_matched, min is 1
+            self.accept_num.append(max_matched)
+            self.n_matched += max_matched - 1
+            self.n_drafted += candidate_length
+
+            # Clean up target model KV cache
+            if max_of_max_matched != max_matched:
+                output_ids = output_ids[:, :max_matched]
+                new_cache_size = max_of_max_matched - max_matched
+                past_key_values = _crop_past_key_values(self, past_key_values, new_cache_size)
+
+            input_ids = torch.cat((input_ids, output_ids), dim=-1)
+
+            step += output_ids.size(1)
+            step_verify += 1
+
+        # Stop on eos and remove content after eos
+        output_ids_list = output_ids[0].tolist()
+        if generation_config.eos_token_id in output_ids_list:
+            idx = output_ids_list.index(generation_config.eos_token_id)
+            step -= (len(output_ids_list) - idx - 1)
+            break
+
+    step = min(step, max_new_tokens)
+    e2e_toc = time.time()
+    self.n_token_generated = step
+    self.e2e_time_without_first = e2e_toc - e2e_tic
+
+    return input_ids[:, : input_len + step]
diff --git a/python/llm/src/ipex_llm/transformers/model.py b/python/llm/src/ipex_llm/transformers/model.py
index 44b2e0ad..13d7d701 100644
--- a/python/llm/src/ipex_llm/transformers/model.py
+++ b/python/llm/src/ipex_llm/transformers/model.py
@@ -330,7 +330,8 @@ class _BaseAutoModelClass:
             model = cls.load_convert(q_k, optimize_model, *args, **kwargs)
 
             if speculative:
-                from .speculative import speculative_generate, clear_benchmarks
+                from .speculative import speculative_generate, clear_benchmarks,\
+                    _crop_past_key_values
                 # load a sym_int4 model as draft model
                 draft_model = cls.load_convert('sym_int4', optimize_model, *args, **kwargs)
                 model.draft_model = draft_model
@@ -338,6 +339,12 @@ class _BaseAutoModelClass:
                 # add speculative_generate to pretrained model dynamically
                 model.clear_benchmarks = types.MethodType(clear_benchmarks, model)
                 model.speculative_generate = types.MethodType(speculative_generate, model)
+                model._crop_past_key_values = types.MethodType(_crop_past_key_values, model)
+
+            # add lookup_generate to pretrained model
+            from .lookup import lookup_generate
+            import types
+            model.lookup_generate = types.MethodType(lookup_generate, model)
         else:
             # load default
             model = cls.HF_Model.from_pretrained(*args, **kwargs)
diff --git a/python/llm/src/ipex_llm/transformers/speculative.py b/python/llm/src/ipex_llm/transformers/speculative.py
index cc9f627e..3d75e5aa 100644
--- a/python/llm/src/ipex_llm/transformers/speculative.py
+++ b/python/llm/src/ipex_llm/transformers/speculative.py
@@ -439,26 +439,49 @@ def _check_and_extend_kv_cache(past_key_values, max_step_draft, kv_alloc_block_l
     return past_key_values, not enough_kv_room
 
 
-@torch.no_grad()
-def speculative_generate(self,
-                         inputs: Optional[torch.Tensor] = None,
-                         draft_model=None,
-                         max_new_tokens=10,
-                         max_step_draft=8,
-                         th_stop_draft=0.8,
-                         auto_th_stop_draft=True,
-                         auto_parameters=[1, 0.5, 0.9, 1e-2, 0.9],
-                         hf_adjust=False,
-                         min_step_draft=3,
-                         generation_config: Optional[GenerationConfig] = None,
-                         attention_mask=None,
-                         **sampling_kwargs):
-    invalidInputError(draft_model is not None,
-                      "Draft model should be provided.")
-    # min_step_draft >= 1. Since the max_step_draft may adjust,
-    # min_step_draft can > max_step_draft
-    min_step_draft = min_step_draft if min_step_draft >= 1 else 1
+def _crop_past_key_values(self, past_key_values, new_cache_size, _enable_ipex=False):
+    if _enable_ipex:
+        cur_len = past_key_values[0][0].size(1)
+        delta = new_cache_size
+        tmp = torch.empty(1, (cur_len - delta), (cur_len - delta), 1,
+                          dtype=torch.long).contiguous()
+        past_key_values = [[tmp, key_cache, value_cache, beam_idx]
+                           for _, key_cache, value_cache, beam_idx in past_key_values]
+    else:
+        if self.config.model_type in ["qwen"]:
+            past_key_values = [
+                (k[:, :-(new_cache_size), :],
+                    v[:, :-(new_cache_size), :])
+                for k, v in past_key_values
+            ]
+        elif self.config.model_type == "chatglm":
+            # for chatglm, cache shape is [sl, bs, nh, hn]
+            past_key_values = [
+                (k[:-(new_cache_size), :, :, :],
+                    v[:-(new_cache_size), :, :, :])
+                for k, v in past_key_values
+            ]
+        elif self.config.model_type in ["baichuan", "gptj"]:
+            past_key_values = [
+                (k[:, :, :-(new_cache_size), :],
+                    v[:, :, :-(new_cache_size), :])
+                for k, v in past_key_values
+            ]
+        elif self.config.model_type == "gpt_bigcode":
+            past_key_values = [
+                kv[:, :-(new_cache_size)]
+                for kv in past_key_values
+            ]
+        else:
+            past_key_values = [
+                (k[:, :, :-(new_cache_size)],
+                    v[:, :, :-(new_cache_size)])
+                for k, v in past_key_values
+            ]
+    return past_key_values
 
+
+def _prepare_generate_args(self, inputs, generation_config, **sampling_kwargs):
     if generation_config is None:
         generation_config = self.generation_config
 
@@ -494,10 +517,27 @@ def speculative_generate(self,
     inputs_tensor, model_input_name, model_kwargs = self._prepare_model_inputs(
         inputs, generation_config.bos_token_id, model_kwargs
     )
-    batch_size = inputs_tensor.shape[0]
 
     # 4. Define other model kwargs
-    # Removed not used
+    # model_kwargs["output_attentions"] = generation_config.output_attentions
+    # model_kwargs["output_hidden_states"] = generation_config.output_hidden_states
+    # # decoder-only models with inputs_embeds forwarding must use caching
+    # # (otherwise we can't detect whether we are generating the first new token or not,
+    # # and we only want to use the embeddings for the first new token)
+    # if not self.config.is_encoder_decoder and model_input_name == "inputs_embeds":
+    #     model_kwargs["use_cache"] = True
+    # else:
+    #     model_kwargs["use_cache"] = generation_config.use_cache
+
+    # accepts_attention_mask = "attention_mask" in set(
+    #     inspect.signature(self.forward).parameters.keys())
+    # requires_attention_mask = "encoder_outputs" not in model_kwargs
+
+    # if model_kwargs.get("attention_mask", None) is None and \
+    #         requires_attention_mask and accepts_attention_mask:
+    #     model_kwargs["attention_mask"] = self._prepare_attention_mask_for_generation(
+    #         inputs_tensor, generation_config.pad_token_id, generation_config.eos_token_id
+    #     )
 
     # decoder-only models should use left-padding for generation
     if not self.config.is_encoder_decoder:
@@ -543,6 +583,61 @@ def speculative_generate(self,
         **model_kwargs,
     )
 
+    return input_ids, generation_config, logits_processor, stopping_criteria, model_kwargs
+
+
+def _non_cpu_ipex_verify(self, verify_input_ids, past_key_values, cur_attention_mask=None,
+                         return_dict=True, use_cache=True):
+    forward_args = {
+        "input_ids": verify_input_ids,
+        "past_key_values": past_key_values,
+        "return_dict": return_dict,
+        "use_cache": use_cache,
+    }
+    if cur_attention_mask:
+        forward_args["attention_mask"] = cur_attention_mask
+
+    if self.config.model_type == "chatglm":
+        past_key_value_len = past_key_values[0][0].shape[0]
+        position_ids = torch.arange(verify_input_ids.shape[1], dtype=torch.long,
+                                    device=verify_input_ids.device)
+        position_ids = position_ids.unsqueeze(0).repeat(1, 1) + past_key_value_len
+        forward_args["position_ids"] = position_ids
+    elif self.config.model_type == "gptj":
+        past_length = past_key_values[0][0].size(2)
+        input_len = verify_input_ids.shape[1]
+        position_ids = torch.arange(past_length, input_len + past_length,
+                                    dtype=torch.long, device=verify_input_ids.device)
+        position_ids = position_ids.unsqueeze(0).view(-1, input_len)
+        forward_args["position_ids"] = position_ids
+
+    return self(**forward_args)
+
+
+@torch.no_grad()
+def speculative_generate(self,
+                         inputs: Optional[torch.Tensor] = None,
+                         draft_model=None,
+                         max_new_tokens=10,
+                         max_step_draft=8,
+                         th_stop_draft=0.8,
+                         auto_th_stop_draft=True,
+                         auto_parameters=[1, 0.5, 0.9, 1e-2, 0.9],
+                         hf_adjust=False,
+                         min_step_draft=3,
+                         generation_config: Optional[GenerationConfig] = None,
+                         attention_mask=None,
+                         **sampling_kwargs):
+    invalidInputError(draft_model is not None,
+                      "Draft model should be provided.")
+    # min_step_draft >= 1. Since the max_step_draft may adjust,
+    # min_step_draft can > max_step_draft
+    min_step_draft = min_step_draft if min_step_draft >= 1 else 1
+
+    input_ids, generation_config, logits_processor, stopping_criteria, \
+        model_kwargs = _prepare_generate_args(self, inputs, generation_config,
+                                              **sampling_kwargs)
+
     step = 0
     step_draft = 0
     step_verify = 0
@@ -851,27 +946,8 @@ def speculative_generate(self,
                 logits = output[0]
                 past_key_values = output[1]
             else:
-                forward_args = {
-                    "input_ids": drafted_input_ids,
-                    "past_key_values": past_key_values,
-                    "attention_mask": cur_attention_mask,
-                    "return_dict": True,
-                    "use_cache": True,
-                }
-                if self.config.model_type == "chatglm":
-                    past_key_value_len = past_key_values[0][0].shape[0]
-                    position_ids = torch.arange(drafted_input_ids.shape[1], dtype=torch.long,
-                                                device=drafted_input_ids.device)
-                    position_ids = position_ids.unsqueeze(0).repeat(1, 1) + past_key_value_len
-                    forward_args["position_ids"] = position_ids
-                elif self.config.model_type == "gptj":
-                    past_length = past_key_values[0][0].size(2)
-                    input_len = drafted_input_ids.shape[1]
-                    position_ids = torch.arange(past_length, input_len + past_length,
-                                                dtype=torch.long, device=drafted_input_ids.device)
-                    position_ids = position_ids.unsqueeze(0).view(-1, input_len)
-                    forward_args["position_ids"] = position_ids
-                output = self(**forward_args)
+                output = _non_cpu_ipex_verify(self, drafted_input_ids, past_key_values,
+                                              cur_attention_mask, return_dict=True, use_cache=True)
             if isinstance(output, dict):
                 logits = output['logits']
                 past_key_values = output['past_key_values']
@@ -939,45 +1015,10 @@ def speculative_generate(self,
             # Clean up target model KV cache
             if max_of_max_matched != max_matched:
                 output_ids = output_ids[:, :max_matched]
-                if _enable_ipex:
-                    cur_len = past_key_values[0][0].size(1)
-                    delta = max_of_max_matched - max_matched
-                    tmp = torch.empty(1, (cur_len - delta), (cur_len - delta), 1,
-                                      dtype=torch.long,
-                                      ).contiguous()
-                    past_key_values = [[tmp, key_cache, value_cache, beam_idx]
-                                       for _, key_cache, value_cache, beam_idx in past_key_values]
-                else:
-                    if self.config.model_type in ["qwen"]:
-                        past_key_values = [
-                            (k[:, :-(max_of_max_matched - max_matched), :],
-                             v[:, :-(max_of_max_matched - max_matched), :])
-                            for k, v in past_key_values
-                        ]
-                    elif self.config.model_type == "chatglm":
-                        # for chatglm, cache shape is [sl, bs, nh, hn]
-                        past_key_values = [
-                            (k[:-(max_of_max_matched - max_matched), :, :, :],
-                             v[:-(max_of_max_matched - max_matched), :, :, :])
-                            for k, v in past_key_values
-                        ]
-                    elif self.config.model_type in ["baichuan", "gptj"]:
-                        past_key_values = [
-                            (k[:, :, :-(max_of_max_matched - max_matched), :],
-                             v[:, :, :-(max_of_max_matched - max_matched), :])
-                            for k, v in past_key_values
-                        ]
-                    elif self.config.model_type == "gpt_bigcode":
-                        past_key_values = [
-                            kv[:, :-(max_of_max_matched - max_matched)]
-                            for kv in past_key_values
-                        ]
-                    else:
-                        past_key_values = [
-                            (k[:, :, :-(max_of_max_matched - max_matched)],
-                             v[:, :, :-(max_of_max_matched - max_matched)])
-                            for k, v in past_key_values
-                        ]
+                new_cache_size = max_of_max_matched - max_matched
+                past_key_values = self._crop_past_key_values(past_key_values,
+                                                             new_cache_size,
+                                                             _enable_ipex)
 
             # Each iter assign new_matched kv_cache to past_key_values1
             if self.device.type == 'cpu' and (not _enable_ipex):