For an n-variable Boolean function, there are 2n fixed polarity Reed-Muller(FPRM) forms. In this paper, a frame of power dissipation estimation for FPRM functions ispresented and the polarity conversion is introduced to minimize the power for FPRM functions.Based on searching the best polarity for low power dissipation, an optimal algorithm is proposedand implemented in C. The algorithm is tested on seven single output functions from MCNCbenchmark circuits. The experimental results are shown in this paper.