Abstract: This acticle put forward the concept of reverse development of CAD. This method uses macro recording function of 3D CAD softwares,because the existence of macro files, the only thing for developer to do is to modify macro files and there is no need to develop too many program codes, so macro files can make the development much easier. This acticle presents an idea of developing parameterization virtual manufacturing system for gears based on CAD software for three-dimensional mechanism SolidWorks97 platform and applying Visual Basic program. Through the idea, the difficult problems of the production of gear virtual designs can be solved, and an approach to developing 3D CAD softwares for mechanism is provided. So devisers can use it in practical development to enhance the ability of developing CAD softwares for three-dimensional mechanisms.