A method for sensing a type of an unbalance of a washing machine is provided. The method may include detecting a vibration amount of a tub using a multi-axis acceleration sensor; detecting a vibration amount of an rpm of a motor; and judging a type of an unbalance based on the vibration amount and the rpm vibration amount. The method may also include detecting a vibration amount of a tub at a plurality of positions of the tub using a plurality of multi-axis acceleration sensors; detecting a time difference of vibration occurrence at the plurality of positions, and thereby calculating a vibration phase difference; and judging a type of an unbalance based on the vibration amount detected at the plurality of positions and the vibration phase difference.