In this paper.an efficient method for constructing array co-processors for onedimensional DFT was proposed. With it.we can construct an array co-processor for 22t points DFT with 2'chips (2'points per chip) and 22tmultiplication units; and an array co-processor for 22t+1 points DFT with 22t+1 chips (2t points per chip) , 22t+1 multiplication units and 22' butterfly operation units.