PURPOSE: To automatically grade the ground by a method in which a controller is set on a reference point, desired shapes of each point are stored in the controller, and the running and attitude of an earthwork machine are controlled by lasers beam emitted on the basis of the stored desired shapes.

CONSTITUTION: A controller 50 provided with a lasers beam emitter (not illustrated) and a memory (not illustrated) is set on a reference point and desired shapes of each point of the ground to be graded are stored in the controller. On the basis of the stored desired shapes, a lasers beam is emitted to measure a relative position with the controller 50 by a distance measurer 44 provided to the earthwork machine 30, and also the beam is received by light receivers 38, 40, and 42 provided to a working machine 32. In the light receivers 38 and 40, the attitude of the machine 32 is controlled, and in the light receiver 42, the steering of the machine 30 is controlled. Since the earthwork machine 30 is automatically operated, the ground can be graded according to a plan even by unskilled operators.