PROBLEM TO BE SOLVED: To provide a self-propelled grass treading machine that prevents plant growth by contact stimulus means.SOLUTION: A grass treading machine automatically travels and prevents growth of weed around a track R. The grass treading machine is characterized as follows: a grass treading plate formed in a flat plate shape or in a shape warped to the front and having a lower surface coming in abutment with a ground surface is provided at the body tip, and a pair of left and right traveling tires and two traveling motors capable of driving the traveling tires alone are provided substantially in the center of the body, respectively; further, a control unit for controlling the drive of the traveling tires and a battery are included in a predetermined place of the body, and the whole weight balance is formed so as to become a stooping posture; and furthermore, a position detection function is provided in a predetermined place of the body or the grass treading plate. The grass treading machine automati
