Abstract: The operation processes of many existing 3D geological modeling methods are often very cumbersome and complex. In order to reduce the labor intensity of technicians, meanwhile, to level up the intuition of the modeling process and to ensure the accuracy of the modeling results, this paper presents a 3D stratum modeling method. It is based on the GIS coordinating to AutoCAD and Google SketchUp. Firstly, the basic principles and the work flow are illustrated intuitively. Next, the process of borehole data processing and the construction of 3D geological scenes are elaborated in detail. Then, the key technologies are discussed in detail. They are related to drawing of stratum surface and boundary face and the construction and visualization of 3D geological stratum models. Finally, a 3D stratum model visualization prototype system has been implemented using C# for representing the constructed 3D stratum models. This system is based on SceneControl. The results of a series experiments show that the modeling method has the characteristics of easy to learn, powerful operability and process-oriented. It is a very practical 3D geological modeling method.