A strap adjustment assembly generally comprises an open or hollow connector frame integrally molded of synthetic resin and a strap retainer integrally molded of synthetic resin and assembled in the hollow connector frame. The hollow connector frame includes a grip base having a strap bearing surface, a pair of spaced legs extending from the grip base and having a pair of oblong slots, respectively, and a connecting bar joining the legs remotely from the grip base by a distance. The strap retainer includes a central strap engagement portion, and a pair of arms extending from the central strap engagement portion and being non-rotatably loosely fitted in the slots, respectively. The central strap engagement portion has a strap pressing surface for frictionally pressing a strap end portion against the strap bearing surface. The strap pressing surface is transversely spaced from the arms at least by said distance. The connector frame and the strap retainer are simultaneously molded in an assembled condition.