Epicyclic gear trains are widely used in various engineering fields, but since the multiple structural types and the complexity of their design work, it is inconvenient for designers to use them. In this paper, a useful tool is developed by using the method of redevelopment of Pro/E (Pro/ENGINEER) based on the AGW (Automation Gateway) which is a kind of linkage software. At first, parameterized 3D models of different kinds of epicyclic gear trains are built in Pro/E, then AGW and Pro/E are linked, and at last through VB (Visual Basic) programming associated with AGW and designing interfaces, designers will be able to control those models according to their needs such as determining the parameters of the gears and calculating the attributes of the epicyclic gear trains, etc. The tool can make both type-selection and design courses more intuitional and convenient comparing with the traditional way.