Abstract: An anti-creep mechanism for coupler includes a lower lockpin rod, a coupler shank and a rotation shaft. The rotation shaft is disposed in an elongate mounting hole of the lower lockpin rod and a circular mounting hole of the coupler shank so that the lower lockpin rod and the coupler shank are hinged together. A boss is axially disposed on an upper surface of the rotation shaft, and a groove is axially provided in a wall of the mounting hole of the coupler shank above the rotation shaft to receive the boss of the rotation shaft. The rotation shaft is axially movable relative to the lower lockpin rod and the coupler shank and has two operating positions. When the rotation shaft is moved to the first operating position, an inner end portion of the boss is positioned in the elongate mounting hole of the lower lockpin rod, and a top wall of this elongate mounting hole abuts against the boss.