The passive vibration control is a very effective measure to gear system. But there exist some limitations. This paper viewed the development of the passive vibration control of gear system, and researched the damping characteristics of the friction dampers and viscoelastic dampers intensively. Firstly, the limitations of the existence passive damping technology are pointed out. Secondly, the feasibility and validity of piezoelectric shunt damping is guaranteed through experimentation on the gear system vibration control. Thirdly, a new hybrid damping, piezoelectric- viscoplastic material damping, is proposed, which extracts the advantages of piezoelectric shunt damping and viscoplastic damping.