Abstract: This paper briefly introduces the forms of the tilting mechanism of tilting car. The models are developed for the kinematics and dynamics analyses also. On the bases of the influences to the tilting function, security, the selection of the tilting actor, space arrangement,etc., the conditions and target of the optimization are determined, and the characteristic parameters of the tilting mechanism are calculated. According to the optimization results, the paper puts forward the selection of the parameters for the tilting mechanism.