A method for sensing vibration of a washing machine including an outer tub installed within a main body, an inner tub rotatably installed within the outer tub, and a motor that drives the inner tub, includes: distributing the laundry put in the inner tub; sensing actual vibration generated when the motor is acceleratedly operated; sensing unbalance mass generated during the accelerated operation of the motor; comparing the sensed actual vibration and the sensed unbalance mass with a reference vibration and a reference unbalance mass; and driving the motor based on the comparison result of the vibration and the unbalance mass. Thus, an unbalance sensing reference which has been set to be too strict more than necessary to sense an abnormal vibration can be mitigated, and thus, time taken for entering the dewatering stroke can be reduced, and because noise smaller than a reference value is generated by limiting vibration of the washing machine during the normal dewatering operation, an agreeable washing environment can be provided to the user.