PURPOSE: To extend the input signal range to form an optical receiving circuit which does not cause waveform distortion, by providing an amplitude detector which detects the output voltage amplitude of a main amplifier and an output control circuit which takes the output voltage of the amplitude detector as the control input to control the output bias potential of a preamplifier.

CONSTITUTION: When the light is made incident on a photoelectric element 1, a photocurrent flowing to the photoelectric element 1 through a transistor TR 5 is generated and the TR 5 is operated by this current, and an output voltage Vop is generated in a TR 6 by this operation. The voltage Vop is amplified by a main amplifier 3 to become an output voltage Vom, and a peak detector 4 detects the peak value of the output voltage Vom, and the base current of a TR 7 is controlled by the detection output. A part of the current flowing through a resistance Rf by the output voltage Vop at this time is the base current of the TR 5, and another part of this current is a current I1 of the TR 7. When the current I1 flows, the bias potential of the output voltage Vop is raised by Rf.I1 if the internal resistance of the TR 7 is ignored.