Stability of power system has been and continues to be of major concern in system operation. Power system stabilizers are designed to enhance the damping of power system oscillations in order to extend power transfer limits of system and maintain the reliable operation of the grid. As a supplementary control to provide extra damping for synchronous generators, power system stabilizer (PSS) has been widely used in the electric power industry. Studies have shown that a well-tuned PSS can effectively improve power system dynamic stability. In this report we have used the design of PSS for single machine infinite bus system using multirate output feedback based digital redesign of sliding mode control, a robust controller design technique, to handel parametric uncertainty in power system and designed PSS for single machine infinite bus power system configuration. © 2008 IEEE.