diff --git a/docs/readthedocs/source/doc/Orca/Overview/distributed-training-inference.md b/docs/readthedocs/source/doc/Orca/Overview/distributed-training-inference.md
index 9a2622ad..ef84a44a 100644
--- a/docs/readthedocs/source/doc/Orca/Overview/distributed-training-inference.md
+++ b/docs/readthedocs/source/doc/Orca/Overview/distributed-training-inference.md
@@ -64,10 +64,10 @@ View the related [Python API doc](https://bigdl.readthedocs.io/en/latest/doc/Pyt
 
 #### **2.2 TensorFlow 2.x and Keras 2.4+**
 
-**Using `tf2` or *Horovod* backend**
+**Using `ray` or *Horovod* backend**
 
 Users can create an `Estimator` for TensorFlow 2.x from a Keras model (using a _Model Creator Function_) when the backend is
-`tf2` (currently default for TF2) or *Horovod*. For example:
+`ray` (currently default for TF2) or *Horovod*. For example:
 
 ```python
 def model_creator(config):
diff --git a/docs/readthedocs/source/doc/PythonAPI/Orca/orca.rst b/docs/readthedocs/source/doc/PythonAPI/Orca/orca.rst
index d378a707..5320a5f7 100644
--- a/docs/readthedocs/source/doc/PythonAPI/Orca/orca.rst
+++ b/docs/readthedocs/source/doc/PythonAPI/Orca/orca.rst
@@ -31,7 +31,7 @@ orca.learn.tf2.estimator
 orca.learn.tf2.tf2_ray_estimator
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Orca TF2Estimator with backend of "horovod" or "tf2".
+Orca TF2Estimator with backend of "horovod" or "ray".
 
 .. autoclass:: bigdl.orca.learn.tf2.ray_estimator.TensorFlow2Estimator
     :members: