An auto exposure control system includes a mean statistics unit that generates a weighted mean brightness value for an image array; a target control unit that determines a target brightness value according to an ambient status that is determined in accordance with an ambient light value, wherein, in one embodiment, the weighted mean brightness value is used as the ambient light value; a stabilization unit that generates stabilization control signals for the target control unit according to the ambient light value and ambient status information provided by the target control unit; and an exposure value control unit that computes a desired exposure value by comparing the target brightness value with the weighted mean brightness value and determines an exposure command according to the desired exposure value.