This paper examines the feasibility of electric power steering system in improving vehicle stability. The electric power steering is the device that decreases the driver steering workload by using an electric motor. In this research, the vehicle dynamics is improved by the method of controlling electric power steering. This paper proposes the feedback control of steering reaction torque for improving vehicle stability. Therefore, the feedback control that utilizes the force on the steering tie rod is proposed for disturbance rejection. Finally, the experiment by using Steering-Hardware-in-the-Loop Simulator (HILS) is conducted to prove the validity of the controller.