Abstract: Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional Power system stabilizers (CPSSs) are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks and related parameters are determined according to a linearized power system model. The performance of CPSSs depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. To overcome the drawbacks of CPSS, numerous techniques have been proposed in literatures. In this paper an optimization method based on Tabu search (SA) is used for tuning the PSS parameters. The performance of proposed SA-PSS is evaluated at IEEE 14 bus test system as a multi machine electric power system. The simulation results clearly indicate the effectiveness and validity of the proposed method