Abstract: A positioning control system for performing recording/reproducing operations by irradiating an optical beam to a predetermined position on an optical recording medium, e.g., magneto-optical disk. The control system includes a photo-detector constituted by at least two-divisional units, and a servo-error signal generating circuit which can generate at least one servo-error signal in accordance with a difference between the detection currents. Preferably, the servo-error signal generating circuit includes at least one division circuit that has two pairs of transistors, two emitters in each pair of transistors being connected together into a common emitter, bias voltages of a direct current type being applied to the respective bases of transistors on one side, and the respective collectors of the transistors on one side being connected to a common connecting portion via resistors.