An image processing system comprises a portable terminal and multiple image processing apparatuses. The portable terminal comprises: a determining portion which determines a target identification operation proving the identify of a target image processing apparatus; a display which displays information about the target identification operation; and an instructing portion which instructs the multiple image processing apparatuses to return answer information. The multiple image processing apparatuses each comprises: a detector which detects that the operation corresponding to the target identification operation has been performed; and a transmitter which transmits to the portable terminal, the answer information and apparatus information. Then the portable terminal further comprises: a receiver which receives the answer information and the apparatus information; and an identifying portion which identifies the target image processing apparatus based on the answer information and the apparatus information.