The invention discloses an impeller for a washing machine. At least one part of a disc face of the impeller is in a hook face shape of which the height is gradually increased in the first direction of the axis of the impeller. Water stirring ribs extending in the radial direction are arranged on the disc face of the impeller. According to the impeller, clothes participating in washing can rise and then fall when the impeller rotates under the stirring of the water stirring ribs, and therefore clothes can be more sufficiently washed, and the cleanness degree of clothes can be increased.