A vehicle seat sliding apparatus comprising: a lower rail fixed to a floor of a vehicle; an upper rail to which a seat is fixed and which is provided so as to allow a relative movement with respect to the lower rail; a locking mechanism configured to be capable of restraining the relative movement of the upper rail with respect to the lower rail; unlocking means configured to cause the locking mechanism to perform an unlocking operation upon a specific seat operation; an unlocked-state maintaining lever configured to maintain the locking mechanism in an unlocked state in cooperation with the unlocking means by moving to a maintaining position in conjunction with the unlocking means; characterised by an unlocked-state releasing lever configured to release the maintenance of the unlocked state, wherein the unlocked-state releasing lever includes: a rotational operating portion configured to rotate in a first direction in conjunction with the unlocked-state maintaining lever moved to the maintaining position and to be capable of coming into contact with an operating member (78, 79) in the direction of the relative movement of the upper rail by the rotation thereof in the first direction, and the unlocked-state releasing lever is configured to press and move the unlocked-state maintaining lever in the direction of releasing the maintenance of the unlocked state by rotating in a second direction opposite from the first direction upon a contact between the rotational operating portion and the operating member (78, 79) and is capable of rotating in the first direction to a position where a rotational operation upon the contact with the operating member is disabled without moving the unlocked-state maintaining lever from the maintaining position. a lower rail fixed to a floor of a vehicle; an upper rail to which a seat is fixed and which is provided so as to allow a relative movement with respect to the lower rail; a locking mechanism configured to be capable of restraining the relative movement of the upper rail with respect to the lower rail; unlocking means configured to cause the locking mechanism to perform an unlocking operation upon a specific seat operation; an unlocked-state maintaining lever configured to maintain the locking mechanism in an unlocked state in cooperation with the unlocking means by moving to a maintaining position in conjunction with the unlocking means; characterised by an unlocked-state releasing lever configured to release the maintenance of the unlocked state, wherein the unlocked-state releasing lever includes: a rotational operating portion configured to rotate in a first direction in conjunction with the unlocked-state maintaining lever moved to the maintaining position and to be capable of coming into contact with an operating member (78, 79) in the direction of the relative movement of the upper rail by the rotation thereof in the first direction, and the unlocked-state releasing lever is configured to press and move the unlocked-state maintaining lever in the direction of releasing the maintenance of the unlocked state by rotating in a second direction opposite from the first direction upon a contact between the rotational operating portion and the operating member (78, 79) and is capable of rotating in the first direction to a position where a rotational operation upon the contact with the operating member is disabled without moving the unlocked-state maintaining lever from the maintaining position. a rotational operating portion configured to rotate in a first direction in conjunction with the unlocked-state maintaining lever moved to the maintaining position and to be capable of coming into contact with an operating member (78, 79) in the direction of the relative movement of the upper rail by the rotation thereof in the first direction, and the unlocked-state releasing lever is configured to press and move the unlocked-state maintaining lever in the direction of releasing the maintenance of the unlocked state by rotating in a second direction opposite from the first direction upon a contact between the rotational operating portion and the operating member (78, 79) and is capable of rotating in the first direction to a position where a rotational operation upon the contact with the operating member is disabled without moving the unlocked-state maintaining lever from the maintaining position.