PURPOSE: To realize a small size of an actuator to lock a driving wheel when a shift lever is operated to a parking range.

CONSTITUTION: While a hydraulic valve 7 is converted, a parking rod 10 is moved, by rotating a control shaft 4 according to the operation of a motor actuator 1. A parking lock cam 12 installed to the parking rod 10 engages a parking lock pole 17 to a parking lock gear 16 when a shift lever is operated to a parking position. In this case, the brake hydraulic rod 19 of a hydraulic actuator 18 makes the parking lock cam 12 escaped from the pressing position to the parking lock pole 17 when a brake pedal is depressed. As a result, as a motor 2 of the motor actuator 1, a small size motor exercising an output only to convert the hydraulic valve 7 can be used.