This paper presents theoretical analysis on maneuverability and stability for four-wheel-steering (4WS) vehicles with lateral acceleration generated by cornering motion. In order to analyze this, a method has been proposed which uses simple linear equations of the vehicle dynamics model approximated by nonlinear equations considering the fluctuation of vertical loads on right and left wheels and characteristics of suspension such as roll steer. It shows that 4WS system through yaw rate feedback control results in improvement in steering response during cornering by the use of this method.