Abstract: A safety belt retractor comprises a belt winding shaft including a cylindrical projecting portion projected from its one end surface, a torsion bar coupled at one end to the end surface of the belt winding shaft and at the other end to a skid mechanism integrated with a sprocket, which is accommodated in the belt winding shaft and the skid mechanism for limiting the torque of the torsion bar, in which the cylindrical projecting portion includes a stopper for determining the rotation of the torsion bar, the skid mechanism includes a skip member, which is provided with a latching portion contacting with the stopper and a skid element for limiting the torque of the torsion bar, and a skid structure provided with a boss coupled to enable the other end of the torsion bar to be inserted thereinto and a guide groove formed around the periphery of the boss on the bottom surface thereof, in which at least two pairs of blocking elements are provided, thereby to limit the rotation of the belt winding shaft.