This paper presents the seismic performance of the steel damper under reversed cyclic loading. The U-shaped steel damper used in this study was designed to have energy dissipation zone with an external diameter of 120 mm, a width of 15 mm, and a thickness of 15 mm. The cyclic loading test was carried out using an uniaxial universal testing machine with a capacity of 2,000 kN. The test results indicated that no strength deterioration of the specimen was found as well as the equivalent damping ratio of the specimen was excellent.