Abstract: In this study, a pulse generation method to trigger the MOSFETs of a shunt active power filter (SAPF) inverter is examined. The proposed method is aimed to compensate current harmonic, as well as reactive power compensation, in power systems with a large concentration of non-linear loads. Design of optimal fuzzy logic controller by genetic algorithm method is presented. Some parameters defining the fuzzy controller (membership functions, fuzzy rules) are optimized simultaneously. In order to investigate the performance of this control method, all studies have been carried out using simulation with the MATLAB Simulink power system toolbox. The results of simulation study of new SAPF control technique presented in this paper are found to be quite satisfactory by assuring good filtering characteristics and high system stability.