To provide a road shoulder-detecting system which can accurately measure the orientation of a vehicle relative to a road shoulder and the distance to the road shoulder. The present invention includes road shoulder-detecting units to scan a road surface in front of a vehicle in the traveling direction of the vehicle and detect a road shoulder located on the road surface and a road shoulder-measuring device to measure the orientation of the vehicle relative to the road shoulder detected by the road shoulder-detecting units and the distance to the road shoulder; and the two road shoulder-detecting units are installed on the traveling direction side of the vehicle. The two road shoulder-detecting units are installed in a higher position than the upper ends of front wheels.