Because of the limitations of network and hardware, early mobile CSCW platform is not used widely. With the continuing escalation of mobile network, the mobile high-speed network of 3G has been constructed completely and the hardware of mobile devices has been upgraded continuously. It provides a good foundation for the mature application of mobile CSCW. This paper presents a framework of mobile CSCW platform for 3G network and describes the specific implementation. In this paper, Web Service, Socket, XML technologies are used to build server-side, and SOAP, HTTPS, SAX, and Socket technologies are used to build client-side. This platform presented in this paper can help enterprises to increase work efficiency in any network environment.