To　improve　seismic　properties,　some　existed　concrete　frames　are　retrofitted　with　Buckling-Restrained　Brace　(BRB).　Considering　the　insufficient　seismic-bearing　capacity　of　the　original　structures,　in-filled　steel　frames　and　connected　BRBs　are　used　to　retrofit.　Three　concrete　frames　are　designed,　built　and　tested.　Two　of　them　are　retrofitted　with　in-filled　steel　frames　and　BRB　(BRBCF),　and　the　other　one　is　an　ordinary　frame,　which　is　designed　for　a　comparison.　Seismic　performance　of　the　frames,　including　the　shear　force-lateral　displacement　hysteretic　curves,　the　skeleton　curves,　the　axial　deformation　loops,　the　statistics　on　equivalent　stiffness　and　the　damping　ratios,　are　tested　and　studied.　The　results　of　the　tests　show　that　the　force-displacement　hysteretic　curves　of　the　retrofitted　frames　are　stable　in　shape;　the　BRB＇s　energy-dissipation　ability　is　stable.　It　is　proved　that　the　load-bearing　capacity　and　structural　damping　can　be　both　increased　in　this　way.　Consequently,　the　in-filled　steel　frames　can　balance　the　load-bearing　capacity　of　BRBs,　which　protect　the　original　frames　from　suffering　more　severe　shear　force,　excavate　the　potential　ductility　of　the　reinforced　concrete　floor　and　beams,　and　improve　the　working　mechanics.　The　seismic　performance　is　improved　obviously.