The present disclosure provides a center hinge assembly for a vehicle rear seat, which includes a lower bracket having a first seating groove formed at one end thereof so that a first shaft or a second shaft is inserted into the first seating groove, and a first locking groove formed at the other end thereof, deeper than the first seating groove, so that a bush fastened to the first or second shaft is inserted and locked into the first locking groove, and an upper bracket having a second seating groove formed at one end thereof so that the first or second shaft is inserted into the second seating groove, and a second locking groove formed at the other end thereof, deeper than the second seating groove, so that the bush is inserted and locked into the second locking groove.