Abstract: The paper mainly introduced whole structure, design of database, real-time data processing and design of Web monitoring interface of a networking system for gas monitoring of coal mine. The system, which is developed by use of Visual Studio, can store real-time data of gas monitoring in Microsoft SQL Server 2005 database and transmit the real-time data based on TCP/IP protocol. Users can remotely monitor real-time gas data of coal mine through Web browser. The application showed validity of the system.