Abstract: An automatic locking type take-up device comprises a base member, a webbing take-up reel rotatably supported by the base member and biased in a direction to take up webbing, an engaging member integrally mounted on the take-up reel, a webbing winding-amount sensing member rotatable in response to rotation of the take-up reel, a lock member movably supported by the base member and capable of assuming a locking position and a non-locking position, a biasing member for biasing the lock member toward the locking position, a first movable member engaged with the winding-amount sensing member, and a second movable member operatively engaged with the first movable member.