To provide an image display system, a terminal device, an image display method and a program in which an image displayed on the screen of the other terminal during telephone conversation is controlled with a simple circuit configuration, and a line transmission capacity is reduced. A self terminal device 100 sends data for switching images displayed on a terminal device 200 at the other end via a network 500 by using an electronic mail, a multi-call function or a discriminating tone. The terminal device 200 controls and switches the images concerning the terminal device 100 within the terminal device 200 based on such various kinds of received information.