A method for detecting a pattern offset amount of exposed regions comprises forming at least one pair of conductive detecting marks with a predetermined position relationship by a patterning process including two exposing processes; detecting an electrical characteristic of the at least one pair conductive detecting marks, if the detected electrical characteristic does not meet a predetermined position relationship, it is determined that the pattern offset amount of the exposed regions in two exposure steps is not qualified; and if the detected electrical characteristic meets the predetermined position relationship, it is determined that the pattern offset amount of the exposed regions in two exposure steps is qualified.