Abstract: This study presents a new generator’s PSS (Power System Stabi1izer) design methodology. A multi input PSS is utilized to achieve a better performance over a wide range of operating conditions instead of a conventional single input PSS. The parameters of the proposed PSS are obtained by minimizing a time domain performance index. The proposed PSS is evaluated against the Conventional Power System Stabilizer (CPSS) at a multi area power system considering system parametric uncertainties. Simulation results show that the proposed PSS provides a better performance than the conventional PSS.