A motor-driven seatbelt apparatus which enables easy re-restraining of a webbing even when an occupant releases the webbing temporarily from a restrained state. A control device senses the vehicle velocity with a vehicle-velocity sensor. When the vehicle velocity is a predetermined value or lower, the control device drives a motor to rotate a winding shaft, so that the webbing is wound into a completely wound state. When the vehicle is traveling at a vehicle velocity exceeding the predetermined value, the storing and winding operation of the winding shaft by the control device or the motor is not performed. Therefore, the occupant who temporarily released the webbing and finished an action such as to take out a small article in the cabin can re-restrain the webbing immediately thereafter.