An advertisement display system includes a means for taking a photograph of a signal light of a signal 5 such as a traffic signal or an alarm for a railway crossing by a photograph unit 1, an analysis means for analyzing the signal condition such as lighting or blinking of the signal light from image data thus photographed by the photograph unit 1 by a computer 2, and a means for displaying an advertisement display information which is stored in advance in the computer 2 or a display unit 3 in conjunction with the lighting or blinking condition of the signal light analyzed by the analysis means and displays a display body having a content correlated with the signal condition of the signal 5 on the display unit 3.