A motion object monitoring system captures images of monitored objects in a monitored area, and gives numbers to the monitored objects according to specific features of the monitored objects. The specific features of the monitored objects are obtained by detecting the captured images. Only one of the numbers of each of the monitored objects is stored, instead of repeatedly storing the numbers of same motion objects. The motion object monitoring system analyzes the stored numbers, and displays an analysis result. The motion object monitoring system also determines a movement of each of the motion objects according to corresponding numbers of the motion objects.