To detect the interferences between tooth profiles in IPMGTD (Internal parallel move gear transmission device)
the model of IPMGTD virtual prototype was built with Pro/E software. Then motion simulation was made to IPMGTD. The models of involute abnormal internal meshing gears were parameterized. The influences of the basic design parameters in the meshing outer gear and the way the internal gear machined were considered when modeling. The results show that the interferences in involute planetary gear drive with small tooth number diffference can be directly detected using virtual prototype technology.