Seat belt connector with tension sensor

A seat belt connector assembly is provided with a seat belt anchor (21) adapted to be coupled to a passenger seat and a cover (11) for accommodating an upper part of the seat belt anchor. The seat belt anchor (21) and the cover (11), which are relatively movable, are each formed with a seat-belt insertion hole (22,23) permitting a seat belt to pass therethrough, and are formed with a mark (25) and a through hole (15), respectively. When the desired relative position permitting the desired tension force to be applied to the seat belt is established between the seat belt anchor (21) and the cover (11), the mark (25) is made visible through the through hole (15).