Firstly,an offset face gear was generated by using a disk wheel,and the topological modification of the gear was achieved through disk wheel's profile modification and center movement control.Secondly,the coordinate systems for grinding and meshing were established,and tooth surface equations of the gear were deduced.Then,by taking into consideration misalignment and topological modification,computational models for tooth contact analysis and loaded tooth contact analysis of the offset face gear pairs were established,and the corresponding computer pro- gram was developed.Finally,some examples were given.The results show that (1) the method of grinding offset face gear with disk wheel is feasible; (2) the tooth surface of the offset face gear is geometrically asymmetrical,and the offset value has an effect on contact patch as well as loaded transmission error but has little influence on transmission error; and (3) the meshing performance of offset face gear pairs can be effectively improved by means of topological modification of the offset face gear.