Hot forging is widely used to manufacture many industrial parts such as machine, automotive and so on. It is important to simulate the relations or characteristics between preform and die before designing the die. The purpose of this study is to investigate the forging characteristics of parking gear with nonlinear gear groove, thus the behaviors of preform can be predicted in advance and finally they can be applied to die design. As the results, since the distributions of high effective strain rate of parking gear were less than 3%, it was predicted that the manufacturing of parking gear with nonlinear gear groove might be possible. Furthermore it was observed that, in this study, the effective stress of bottom die was lower than that of top die.