A methodology to build 3D urban visualization system is suggested

and optimized solutions to key problems are studied.Real estate data

cadastral data

and city planning data are the fundamental data.The data of buildings

roads

water system and topography are extracted

and they are used to build urban 3D visualization models.Texture data collected with digital camera are integrated with 3D building model to generate high resolution urban visualization data.Visualization procedures are developed with Visual C++6 0 and OpenGL to visualization the 3D data.With the help of this methodology

the 3D visualization system of Yangzhou Economic Development Region is constructed

and the efficiency of the methodology is proved.