This invention relates to a method for braking a washing machine comprising the steps of: determining whether or not a motor is braking; transmitting a PWM (Pulse Width Modulation) control signal by setting up the initial phase and the duty ratio according to the voltage flows in the system when an operation mode determined by the previous step as a braking mode; comparing a capacity and a variance of the detected voltage with a reference voltage predetermined during the previous step; and controlling a motor driver by re-establishing the control phase and the duty ratio are re-established until the motor is stopped when the comparison result of the previous step indicates that the capacity and the variance of the voltage are lower than the predetermined reference level.