To provide an optical communication system constituted achieving optical communication without reducing luminance of an LED lamp and preventing a corner from being blind with respect to a traffic signal.

Lighting of lamps 2a, 2b, 2c in each of colors of red, yellow and blue of an LED traffic signal 2 is controlled by a traffic signal control panel 3 and a transmitter 10. The transmitter 10 drives the LED lamp being lit by a coded signal Sc formed by coding transmitted data Ds. A vehicle running toward the LED traffic signal is mounted with a receiver 20 having a camera 21 which photographs a plurality of LED traffic signals 2; an image processing part 22 performs processing for converting the photographed image into an HVC color system from RGB, signal color filter processing and circular shape recognition processing and a decoding part 24 which extracts an optical signal to decode it from a blinking part on the basis of the processing result of circular shape recognition.