A washing machine and a method for supplying water thereof are disclosed. The washing machine comprises a supply valve for supplying cold/warm water into a tub, a water level detection unit for detecting a water level in the tub, and a microcomputer for performing an intermittent water supply and a continuous water supply by controlling an amount of water supplied to the tub from the water supply valve via a detergent barrel, and for controlling water supply according to the water level in the tub detected by the water level detection unit. The intermittent and continuous water supply is performed in such a manner of supplying water and stopping the water supply, and water supply time is differently set for the primary and secondary intermittent water supply, so that the detergent can be smoothly supplied to the tub without remaining in the barrel.