An automatic seatbelt system for automatically fastening an outer webbing and an inner webbing to an occupant upon being seated, wherein opposite ends of the outer webbing are engaged with the upper and lower portions of a vehicle door, respectively, the base portion of the inner webbing is wound into a retractor provided at substantially the central portion of the vehicle, and, in an emergency of a vehicle, the intermediate portion of the inner webbing is directly locked, so that the inner webbing can be prevented from being wound out of the retractor. Further, the forward end of the inner webbing is adapted to guide the intermediate portion of the inner webbing through a through-ring, prevent the outer webbing from moving in the longitudinal direction thereof to improve the occupant restraining characteristics in an emergency of a vehicle, and the intermediate portion of the inner webbing is moved forward in the vehicle when the occupant enters or leaves the vehicle to facilitate actions of the occupant in entering or leaving the vehicle.