Four-wheel steering (4WS) is an advanced vehicle control technique which can improve steering characteristics. Compared with traditional two wheel steering (2WS) vehicles, 4WS vehicle can steer the front wheels and the rear wheels individually when cornering, according to the vehicle motion states such as vehicle speed, yaw velocity and lateral acceleration. Therefore, 4WS can enhance the handling stability and improve the active safety for vehicle. In this paper, the motion characteristics of 4WS vehicle are analyzed. The steering dynamics model of vehicle is established, and the transfer function of deflection angle of mass center to steering angle of 4WS vehicle is deduced. The handling stability of 4WS vehicle is researched by virtue of Matlab/simulink, Simulation results show that the 4WS vehicle is agile to and consistent with steering input and the transient handling stability is improved distinctly without increasing driver’s handling burden.