Abstract: This paper presents the seismic retrofit of a 4-story reinforced concrete frame with buckling-restrained braces(BRB),including comparison the seismic effects between the original structure and the retrofitted structure using response spectra analysis and history analysis under the frequent earthquakes and the basic earthquakes.The results indicate that: the BRBs can improve aseismatic capacity of the structure;when subjected to the frequent earthquakes,the BRBs are in elastic state,providing the stiffness for the main structure;when subjected to the basic earthquakes,the BRBs in the structure are in non-lined state,providing the energy-dissipation capacity.