In this paper, we are going to deal about the enhancement of system stability, by using Eigen-values we can say how system stability is varying. We can use different devices like Facts controllers, Power system stabilizers, and automatic voltage regulators to improve system stability. Power system stabilizer had been used for improving two machine three bus system stability. We have different linear and nonlinear methods to design controller parameters for power system stabilizers. Genetic algorithm technique had been used to design pss for two machine three bus system