The damage diagnosis from remote administration is demanded as an example of maintenance business. For the reason, many researches have dealt with a damage diagnosis on tooth surface of gears by using vibration or noise data. However, this diagnosis method is difficult to detect an abnormal tooth early on. Therefore, we develop a method to diagnose by using a laser beam from the point of view of remote diagnosis. The variations of laser reflection between the initial and the present conditions are compared, and it can estimate a condition on tooth surface such as initial or abnormal abrasion, pitting, spalling, etc. In this paper, we verified the method to diagnose the location and size of pitting on the tooth surface.