Seat sliding device for vehicle

A seat sliding device for a vehicle (1) for unlocking or retaining an unlocked state of a pair of movable rails (4, 35) that supports a seat (3) relative to a pair of fixed rails (2, 34) either by tilting a seat back (31) in a forward direction or by operating an operating handle (18). The seat sliding device comprises a link mechanism (36) provided at one cooperating pair of the rails and a lock mechanism provided at the other cooperating pair of the rails, wherein after the seat (30) is moved in the forward direction with the seat back (31) being turned forward, the link mechanism (36) makes the lock mechanism (1) inoperative so that the seat (30) can be moved in a rearward direction regardless of the upright or tilted state of the seat back (31).