Abstract: In order to bring improve the aseismatic performance of the common concentrically,based on the researches on the buckling-restrained brace and common concentrically braced steel frames,it was adopt to improve common concentrically braced steel frames.,and achieve the seismic fortification goal.Thus aseismatic performance of the main structure was kept elastic characteristic under the middle seism on the condition that the quantity of steel didn't increase.First the method and the steps were listed.Second taking a multi-story concentrically braced steel frames for example,reasonable buckling-restrained brace was selected.Hand computation and the pushover analyses are carried.Finally it was proved that this way listed in this paper was feasible.