Monte Carlo simulation on the cathode spot movement and the erosion pattern for Au contact was carried out by employing the micro-computer. Three factors which were applied to characterize the cathode spot bahavior of the break arcs, which are the maximum length moved, the maximum moving width and the velocity distributions of moving cathode spot, and arc duration were established as the restriction conditions for this simulation. The simulation on the cathode spot movement on (x y) surface the contour figures and the cross sections of crater structures were in good agreement with the actual results of the cathode spot behavior and the erosion pattern on Au contacts.