An experimental system of the autonomous mobile robot witch follows a people or other robots was implemented and demonstrated in various situation. For this purpose, an algorithm to track an object by the moving sensor is considered and designed. In this method, SOKUIKI sensor (Scanning Laser Range Finder) output are combined with odometry data, in order to find the particular target object the others, and to estimate the target object motion. The many experimental have shown the robust target object following ability of this system.