A specialized CAD/CAM system of bevel gear for car differential mechanism is developed by using the secondary development tools of UG/Open API

UG/Open UIStyler and UG/Open MenuScript

and integrated development environment Visual C++ 6.0.The system utilizes parameterized modeling technology to obtain a 3D gear model

and improve the design quality and design efficiency.The correlation modes between components are realized with UG WAVE technology.The use of database technique ensures the stability of values of parameters and the attribute during processing.The system realizes the integration of UG system by means of the function for the internal call DLL（Dynamic Link Library）.At last the machining process of gear die is simulated in the numerical control module and the G code of the machining tool path is generated.