The automatic focusing system disclosed is characterized that the focusing condition of an objective lens to be focused is repeatedly detected with the objective lens being moved, and that defocus signals, each representing a defocus direction and a defocus amount of the lens according to the focusing condition upon each detection, are processed in a predetermined statistic method to produce a final signal. The final signal is effected for controlling the axial position of the objective lens to lead the lens to its infocus position. Therefore, the automatic focusing system according to the present invention achieves the high accuracy of focusing and quickness thereof.