diff --git a/README.md b/README.md
index d816fde..d3449dd 100644
--- a/README.md
+++ b/README.md
@@ -1,31 +1,50 @@
 ## WebSSH
+
 [![Build Status](https://travis-ci.org/huashengdun/webssh.svg?branch=master)](https://travis-ci.org/huashengdun/webssh)
 [![codecov](https://codecov.io/gh/huashengdun/webssh/branch/master/graph/badge.svg)](https://codecov.io/gh/huashengdun/webssh)
 ![PyPI - Python Version](https://img.shields.io/pypi/pyversions/webssh.svg)
 ![PyPI](https://img.shields.io/pypi/v/webssh.svg)
 
+
+## Introduction
+
 A simple web application to be used as an ssh client to connect to your ssh servers. It is written in Python, base on tornado and paramiko.
+```
++---------+     http     +--------+    ssh    +-----------+                         
+| browser | <==========> | webssh | <=======> | ssh server|
++---------+   websocket  +--------+    ssh    +-----------+
+```
 
-### Preview
-![Login](https://github.com/huashengdun/webssh/raw/master/preview/login.png)
-![Terminal](https://github.com/huashengdun/webssh/raw/master/preview/terminal.png)
+## Features
 
-### Features
 * SSH password authentication supported, including empty password.
 * SSH public-key authentication supported, including DSA RSA ECDSA Ed25519 keys.
 * Encrypted keys supported.
 * Fullscreen terminal supported.
 * Terminal window resizable.
-* Auto detect system default encoding.
-* Compatible with Python 2.7-3.7.
+* Auto detect the ssh server's default encoding.
+
+
+## Preview
+
+![Login](https://github.com/huashengdun/webssh/raw/master/preview/login.png)
+![Terminal](https://github.com/huashengdun/webssh/raw/master/preview/terminal.png)
+
+
+### Requirement
+
+* Python 2.7/3.4+
+
 
 ### Instructions
+
 ```
 pip install webssh
 wssh
 ```
 
 ### Options
+
 ```
 # listen address and port
 wssh --address='0.0.0.0' --port=8000
@@ -41,9 +60,22 @@ wssh --log-file-prefix=main.log
 
 # more options
 wssh --help
-```````
+```
+
+### Tests
+
+Use unittest for running all tests
+```
+python -m unittest discover tests
+```
+
+Use pytest for running all tests
+```
+python -m pytest tests
+```
+
+### An example of config  for running this app behind an Nginx server
 
-### Nginx config example for running this app behind an nginx server
 ```
 location / {
     proxy_pass http://127.0.0.1:8888;
@@ -57,6 +89,7 @@ location / {
 }
 ```
 
-### Tips
+## Tips
+
 * Try to use Nginx as a front web server (see config example above) and enable SSL, this will prevent your ssh credentials from being uncovered. Also afterwards the communication between your browser and the web server will be encrypted as they use secured websockets.
 * Try to use reject policy as the missing host key policy along with your verified known_hosts, this will prevent man-in-the-middle attacks. The idea is that it checks the system host keys file("~/.ssh/known_hosts") and the application host keys file("./known_hosts") in order, if the ssh server's hostname is not found or the key is not matched, the connection will be aborted.
diff --git a/README.rst b/README.rst
index 701c377..b2af13b 100644
--- a/README.rst
+++ b/README.rst
@@ -3,16 +3,20 @@ WebSSH
 
 |Build Status| |codecov| |PyPI - Python Version| |PyPI|
 
+Introduction
+------------
+
 A simple web application to be used as an ssh client to connect to your
 ssh servers. It is written in Python, base on tornado and paramiko.
 
-Preview
-~~~~~~~
+::
 
-|Login| |Terminal|
+    +---------+     http     +--------+    ssh    +-----------+                         
+    | browser | <==========> | webssh | <=======> | ssh server|
+    +---------+   websocket  +--------+    ssh    +-----------+
 
 Features
-~~~~~~~~
+--------
 
 -  SSH password authentication supported, including empty password.
 -  SSH public-key authentication supported, including DSA RSA ECDSA
@@ -20,8 +24,17 @@ Features
 -  Encrypted keys supported.
 -  Fullscreen terminal supported.
 -  Terminal window resizable.
--  Auto detect system default encoding.
--  Compatible with Python 2.7-3.7.
+-  Auto detect the ssh server's default encoding.
+
+Preview
+-------
+
+|Login| |Terminal|
+
+Requirement
+~~~~~~~~~~~
+
+-  Python 2.7/3.4+
 
 Instructions
 ~~~~~~~~~~~~
@@ -51,7 +64,22 @@ Options
     # more options
     wssh --help
 
-Nginx config example for running this app behind an nginx server
+Tests
+~~~~~
+
+Use unittest for running all tests
+
+::
+
+    python -m unittest discover tests
+
+Use pytest for running all tests
+
+::
+
+    python -m pytest tests
+
+An example of config for running this app behind an Nginx server
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ::
@@ -68,7 +96,7 @@ Nginx config example for running this app behind an nginx server
     }
 
 Tips
-~~~~
+----
 
 -  Try to use Nginx as a front web server (see config example above) and
    enable SSL, this will prevent your ssh credentials from being