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.