An imaging object tracking system includes an entrance/exit detection camera to take an image of an entrance/exit detection area where an imaging object enters and exits, an entrance/exit detection upper sensor to detect the imaging object being imaged by the entrance/exit detection camera, at least one upper sensor disposed so as to overlap a part of the detection area for detecting the imaging object with an area where the entrance/exit detection upper sensor detects the imaging object, an initial position estimation unit to estimate an initial position of the imaging object on the basis of positional coordinates of the imaging object in a two-dimensional image taken by the entrance/exit detection camera and three-dimensional coordinate information of the entrance/exit detection area, an upper position detection unit to detect a position of the imaging object seen from an upper side thereof, an initial motion path generation unit to generate an initial motion path, and a tracking unit to generate a following motion path by adding a position of the imaging object to the initial motion path.