An information display system capable of reducing a trouble about display caused by display of content information corresponding to numerous markers and reducing process loads and a control method of the information display system are provided. In this system, a movement speed and a movement direction of a client apparatus operated by a user are detected, and a size and a position of a marker recognition area for recognizing a marker in an imaged image are determined according to the detected movement speed and the detected movement direction. Then, the content information corresponding to the marker recognized in the marker recognition area is superposed on the imaged image and output to a display screen.