Technology of 3D GIS had developed rapidly and obtained widespread attention.Compared with two-dimensional GIS,3D GIS represents natural world more vividly.Moreover,it has specific functions of 3D displaying,analyzing and operating on spatial objects under a 3D system.Taking Nanjing University of Information Science and Technology as an example,introduced the modelling simulation process of virtual campus based on 3D GIS.It also discussed the key issues which are the essential technology and method of virtual campus simulation about 3D visualization on 3D-scene modelling,modelling optimization and system development design based on Google SketchUp and ArcGIS.The development of functional modules consists of four sub modules,namely 3D scene viewing,attributes query of buildings,path analysis and animation outputting.Finally,the paper addresses some problems involved in this system,and puts forward thoughts for further study.