Abstract A type of dissipative device referred to as a “dual function” metallic damper was presented in this paper. These types of metallic dampers are referred to as “dual function” metallic dampers (DFMDs), because they provide additional structural stiffness, and also have fairly good seismic energy-dissipation capabilities. Quasi-static tests with these types of metallic dampers were carried out. Furthermore, a steel structure with dampers was tested on a shaking table under four earthquake ground motion records of various amplitudes to study the dynamic characteristic and seismic response. More specifically, these tests are performed in order to estimate the effects of dampers on the seismic behaviors of the structure. A building with actual “dual function” metallic dampers was also introduced, and the finite element model of this building was made with the ADPL language in the ANSYS program. Seismic responses of the building with and without the metallic dampers are discussed and compared. The results of test and calculated methods show that the metallic dampers with “dual functions” presented here not only provide the added structural stiffness, but also have good seismic energy dissipation capabilities.