In a vehicle in which an engine output power is transmitted to front and rear wheels through a transmission and an inter axle differential, a wheel lock prevention device is provided. The wheel lock prevention device comprises a differential lock mechanism for locking the inter axle differential, a detection element for detecting a wheel lock state of the front and rear wheels, and an operation element for operating the differential lock mechanism so as to lock the inter axle differential by operating the differential lock mechanism upon the detection of the wheel lock state.