PURPOSE: To realize an optical communication device in which the filter circuit giving the approximation to the cable's characteristics is provided at the transmission/ reception end in order to aviod the change of the electric preperty of the whole system in case the optical communication system is introduced to a part of the cable communication via the electric conductor.

CONSTITUTION: The electric input signal supplied from terminal 1 is applied to modulator 3 via filter 8 which gives the approximation to the transmission characteristics of the cable via the electric conductor. Modulator 3 gives the modulation to the optical output given from light source 2 via the signal sent from filter 8 and then transmits the output to optical transmission line 4 of the optical fiber or the like. Optical-electric signal converting circuit 5 converts the optical signal sent from line 4 into the electric signal to apply the electric signal to output circuit 6. The filter 8 can be provided at the reception end or both the transmission and the reception ends.