Abstract: The need for 3D city reconstruction is obvious, so there is a big demand for this very special data coming from city planners, architects, electrical engineers and telecommunication people, and last not least from tourists.With the invention of the World Wide Web (WWW) data of all kind are made accessible to everybody who is linked to a WWW Server.The WWW is an information discovery system for browsing and searching the Internet WWW of digital information.At the mean time, there are many comments about the needed evolution of current day tools like GIS that are used to integrate the collection, storage, retrieval, manipulation and display of spatial data. In this paper, the concepts about the CyberCity and the corresponding technique supports and typical applications are introduced. CCGIS, the GIS for CyberCity, is developed by WTUSM in China.By means of CCGIS, the 3D city model based on DPW, CAD or GIS data can be created semi-automatically, and the multitypes databases can also be seamlessly integrated.CCGIS includes not only most of the traditional GIS functions like spatial query, multimedia expression, but also the real-time 3D animation, and so on.As the pilot projects, the applications of CCGIS software in CyberShenzhen and CyberShanghai are also presented. At last, some of key technologies such as the reconstruction of 3D city model, vast amount of data integration and its real-time application of 3D animation are discussed.