diff --git a/.github/workflows/python-publish.yml b/.github/workflows/python-publish.yml
index 08d41d198..8b94a2d3b 100644
--- a/.github/workflows/python-publish.yml
+++ b/.github/workflows/python-publish.yml
@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         os: [windows-latest, macos-latest]
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 637b0c291..eab6607b1 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         os: [windows-latest, ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, macos-latest]
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2
diff --git a/README.md b/README.md
index 9e3bfce09..25090fc01 100644
--- a/README.md
+++ b/README.md
@@ -149,6 +149,10 @@ Qlib provides a tool named `qrun` to run the whole workflow automatically (inclu
       cd examples  # Avoid running program under the directory contains `qlib`
       qrun benchmarks/LightGBM/workflow_config_lightgbm_Alpha158.yaml
     ```
+    If users want to use `qrun` under debug mode, please use the following command:
+    ```bash
+    python -m pdb qlib/workflow/cli.py examples/benchmarks/LightGBM/workflow_config_lightgbm_Alpha158.yaml
+    ```
     The result of `qrun` is as follows, please refer to [Intraday Trading](https://qlib.readthedocs.io/en/latest/component/backtest.html) for more details about the result. 
 
     ```bash
diff --git a/docs/component/recorder.rst b/docs/component/recorder.rst
index baf8f2bca..5e01140cf 100644
--- a/docs/component/recorder.rst
+++ b/docs/component/recorder.rst
@@ -34,8 +34,9 @@ Here is a general view of the structure of the system:
             - Recorder 2
             - ...
         - ...
-This experiment management system defines a set of interface and provided a concrete implementation based on the machine learning platform: ``MLFlow`` (`link <https://mlflow.org/>`_). 
+This experiment management system defines a set of interface and provided a concrete implementation ``MLflowExpManager``, which is based on the machine learning platform: ``MLFlow`` (`link <https://mlflow.org/>`_). 
 
+If users set the implementation of ``ExpManager`` to be ``MLflowExpManager``, they can use the command `mlflow ui` to visualize and check the experiment results. For more information, pleaes refer to the related documents `here <https://www.mlflow.org/docs/latest/cli.html#mlflow-ui>`_.
 
 Qlib Recorder
 ===================
diff --git a/docs/component/workflow.rst b/docs/component/workflow.rst
index 5b81c7e78..96a764de1 100644
--- a/docs/component/workflow.rst
+++ b/docs/component/workflow.rst
@@ -103,6 +103,12 @@ After saving the config into `configuration.yaml`, users could start the workflo
 
     qrun configuration.yaml
 
+If users want to use ``qrun`` under debug mode, please use the following command:
+
+.. code-block:: bash
+
+    python -m pdb qlib/workflow/cli.py examples/benchmarks/LightGBM/workflow_config_lightgbm_Alpha158.yaml
+
 .. note:: 
 
     `qrun` will be placed in your $PATH directory when installing ``Qlib``.
diff --git a/setup.py b/setup.py
index 109a6b032..b959f6c1c 100644
--- a/setup.py
+++ b/setup.py
@@ -46,7 +46,7 @@ REQUIRED = [
     "statsmodels",
     "xlrd>=1.0.0",
     "plotly==4.12.0",
-    "matplotlib==3.1.3",
+    "matplotlib==3.3.3",
     "tables>=3.6.1",
     "pyyaml>=5.3.1",
     "mlflow>=1.12.1",
@@ -119,5 +119,6 @@ setup(
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
     ],
 )