This study compares the power system stabilizer based on sliding mode control with the fuzzy power system stabilizer for Single Machine Infinite Bus System (SMIB). Using the sliding mode control, a range is obtained for the changes in system parameters and a stabilizer is designed to have a proper performance in this wide range-This study compares the power system stabilizer based on sliding mode control with the fuzzy power system stabilizer for Single Machine Infinite Bus System (SMIB). Using the sliding mode control, a range is obtained for the changes in system parameters　and a stabilizer is designed to have a proper performance in this wide range