A washing machine includes a motor for generating power and a clutch assembly that receives the power from the motor and drives a drum and a pulsator. The clutch assembly includes a driving shaft that receives the power from the motor and rotates, a pulsator drive portion selectively receiving the power from the driving shaft to rotate the pulsator, and a drum driving portion selectively receiving the power from the driving shaft to rotate the drum, The clutch assembly is provided to selectively drive a driving portion of at least one of the drum driving portion and the pulsator drive portion. With this configuration, the washing machine capable of running various modes of a washing mode and dehydration mode is implemented.