Abstract: A belt retractor is disclosed which includes a rotary shaft having thereon a belt reel with a coil of seat belt wound therearound. The rotary shaft is rotatable in a first direction when the seat belt is pulled out and is spring-biased for rotation in a second direction to retract the seat belt around the belt reel. Lock means is provided for locking the rotary shaft so that the rotary shaft is prevented from rotating in the second direction but permitted to rotate through a predetermined angle in the first direction and to rotate back through the permitted angle in the second direction. Drive means is provided for bringing the lock means into driving connection with the rotary shaft when the seat belt is being worn around the user.