A laundry treating apparatus includes: a tub; a drum; an agitator disposed in the drum; a stator; a rotor configured to rotate relative to the stator; a drum-rotating shaft coupled to the drum; an agitator-rotating shaft coupled to the rotor and the agitator; a first serration disposed at an end of the agitator-rotating shaft; a second serration disposed at an end of the drum-rotating shaft; a fixed body fixed between the tub and the rotor; a support body rotatably disposed within the fixed body; a body-driving system configured to move the support body relative to the fixed body; and a shaft-joint configured to reciprocate between a first point and a second point of the support body. The shaft-joint is configured to engage the first serration to the second serration at the first point, and decouple the first serration from the second serration at the second point.