Abstract: In the application of phase array antennas, the different side lobes level in each side of the antenna-array pattern iswanted to achieve some especial purpose. Meanwhile we try to reduce the number of parameters of phase variable to save thememory of the wave control machine and we still can complete the beam forming. In this paper we proposed the differentialevolution (DE) algorithm to optimize array excitation parameters including 16amplitudes variable and 1 phase variable. The resultsof SLLs in each side of the antenna-array pattern are -25 dB and -35dB.