Provided is a seat cover (5) of a vehicle seat (1) which is formed by sewing a plurality of skin materials includes: a locked part (23) which is provided in a sewn portion (12) of two sheets of sewn skin materials (10 and 11) and is locked in a locking part (22) of a cushion pad in a state where the sewn portion is pulled into a cushion pad (20). Among seam allowances of the skin materials included in the sewn portion, a seam allowance (14) of one skin material includes a protrusion part (15) which is arranged to protrude in a pulling-in direction of the sewn portion from a seam allowance (13) of the other skin material. The locked part is directly provided in the protrusion part.