A motor control method for controlling a motor of an electric power assisted steering system includes: generating a low pass torque signal and a high pass torque signal, respectively; generating a low frequency assist torque signal using the low pass torque signal and the vehicle speed; generating a high frequency assist torque signal using a high pass torque signal and the vehicle speed; generating a torque command signal using a sum of the low frequency assist torque signal and the high frequency assist torque signal; and generating a voltage output signal for driving the motor using the torque command signal.