The Visual Basic program of standard straight bevel gear's parametric design based on Solidworks software was completed. The geometric features of bevel gears were analyzed, parametric design variables were defined, each control point was determined in Cartesian Coordinate System. In development of the system, the API functions such as CreatLine, FeatureRevolve,FeatureCut, CreatePlaneAtAngle3, InsertCutBlend and FeatureCircularPattern were used; the involute profiles of bevel gear at large end were fit by splines. The parametric design of bevel gears may provide a basis for further finite element stress analysis or assembly.