For many years, optic scientists have been looking for all-optical signal processing materials that enable one light beam to be controlled by another. All optical logic gates are the building blocks of optical signal processing devices. In this paper, the authors propose all optical universal logic gates NAND and NOR gates based on Four-Wave Mixing (FWM) in SOA. Logic levels at the output will be differentiated by the output power. Simulation has been performed at 40Gb/s and extinction ratio achieved for NOR gate is 7.5dB and for NAND gate is 8.75dB.