A dust detection system, comprising a receiver, a dust extraction block, a memory and an image correction block, is provided. The receiver receives an image signal. The dust extraction block generates a dust image signal on the basis of the image signal. The memory stores an intrinsic-flaw image signal corresponding to an intrinsic-flaw image including sub-images of dust that the dust extraction block extracts in initializing. The image correction block generates a corrected dust-image signal on the basis of the intrinsic-flaw image signal and a normal dust-image signal. The normal dust-image signal corresponds to a normal dust image including sub-image of dust that the dust extraction block extracts after initializing. The corrected dust image is the normal dust image that sub-images of dust in the intrinsic-flaw image are deleted from.