A vehicle seat reclining device comprising: a lower arm adapted to be held on a side of a seat cushion of a vehicle seat; an upper arm adapted to be held on a side of a seatback of the vehicle seat; an internal gear formed on a first arm comprising either one of the lower arm and the upper arm; an external gear formed on a second arm comprising the other of the lower arm and the upper arm to be meshed with the internal gear and being fewer in number of teeth by at least one tooth than the internal gear; first and second wedge members (7a,7b) frictionally engageable with the first arm and frictionally disengageable therefrom; a spring arranged between the first wedge member and the second wedge member and urging the first and second wedge members at all times in a direction for friction engagement with the first arm; a drive shaft provided with a drive portion for moving either one of the first wedge member and the second wedge member against the resilient force of the spring in a direction to release the friction engagement and for rotating the first and second wedge members through the spring about the rotational axis of the first arm; and a ring member arranged between the second arm and the first and second wedge members to be relatively rotatable for rotating together with the first and second wedge members relative to the second arm and characterized in that the ring member is arranged to be rotatingly driven at the same time in accordance with a movement of the first and second wedge members when an end surface of the ring member is brought into contact with the other of the first and second wedge members upon rotation of the drive portion; wherein, upon rotation of the drive shaft, the first and second wedge members are rotated relative to the first arm to make the ring member revolve around the rotational axis of the first arm, the second arm is eccentrically moved relative to the first arm to turn the upper arm relative to the lower arm in dependence on the difference in number of teeth between the internal gear and the external gear. a lower arm adapted to be held on a side of a seat cushion of a vehicle seat; an upper arm adapted to be held on a side of a seatback of the vehicle seat; an internal gear formed on a first arm comprising either one of the lower arm and the upper arm; an external gear formed on a second arm comprising the other of the lower arm and the upper arm to be meshed with the internal gear and being fewer in number of teeth by at least one tooth than the internal gear; first and second wedge members (7a,7b) frictionally engageable with the first arm and frictionally disengageable therefrom; a spring arranged between the first wedge member and the second wedge member and urging the first and second wedge members at all times in a direction for friction engagement with the first arm; a drive shaft provided with a drive portion for moving either one of the first wedge member and the second wedge member against the resilient force of the spring in a direction to release the friction engagement and for rotating the first and second wedge members through the spring about the rotational axis of the first arm; and a ring member arranged between the second arm and the first and second wedge members to be relatively rotatable for rotating together with the first and second wedge members relative to the second arm and characterized in that the ring member is arranged to be rotatingly driven at the same time in accordance with a movement of the first and second wedge members when an end surface of the ring member is brought into contact with the other of the first and second wedge members upon rotation of the drive portion; wherein, upon rotation of the drive shaft, the first and second wedge members are rotated relative to the first arm to make the ring member revolve around the rotational axis of the first arm, the second arm is eccentrically moved relative to the first arm to turn the upper arm relative to the lower arm in dependence on the difference in number of teeth between the internal gear and the external gear.