1. Define a schema file: **.xsd

2. create class for this schema file

2.1 find the location of schema file

2.2 start "Visual Studio Command Prompt" under VS2010 tools

2.3 switch current location to location of schema file

2.4 run command as below: 

xsd schema /class

3. remove schema file from solution

4. reload schema to solution and then we can see that

there is a cs file contains class under schema file

5. create XML file according to schema

6. new "schema class" to load XML file and then we can use the data in XML file directly.

Thank you, Jerry.

He help me clear it.