Abstract: In the application of multimedia, the multiplier accumulator is the device of main operation, so a new design of the MAC is presented. It is mainly made up by two 8 bits by 8 bits multipliers, and can be used to calculate three types of multiply accumulate operations. The first is signed or unsigned 16b×16b; the second is signed or unsigned 16b×8b, 8b×16b or 8b×8b; the third is two simultaneity signed or unsigned 8b×8b. All of the operations mentioned above can be performed by one cycle except the first one that needs two cycles, and it is better than the other two methods at the trade off of AT 2 and power dissipation.