The　installation　of　a　damping　bracing　system　is　regarded　as　an　effective　means　to　upgrade　the　seismic　capacity　of　steel　moment-resisting　frames　(MRFs),　a　common　structural　form　for　buildings.　However,　conventional　damping　braces　are　incapable　of　eliminating　residual　deformation　demand.　Shape　memory　alloy　(SMA)　braces　present　an　emerging　seismic　upgrading　solution　to　this　problem.　However,　the　corresponding　design　method　is　yet　to　be　developed.　Therefore,　this　study　proposes　a　simple　and　straightforward　design　method　for　seismic　upgrading　of　MRFs　through　the　installation　of　SMA　braces.　The　maximum　and　residual　interstory　drift　ratios　are　selected　as　performance　target.　Two　benchmark　frames　with　three　or　six　stories　are　adopted　to　validate　the　proposed　design　method.　A　group　of　seismic　ground　motions　corresponding　to　the　design　basis　earthquake　level　are　input　to　the　frames　with　or　without　SMA　braces.　Seismic　analysis　results　indicate　that　the　frames　equipped　with　properly　designed　SMA　braces　exhibit　responses　that　satisfy　the　design　target　satisfactory.　To　quantify　the　seismic　upgrading　effect,　peak　and　residual　interstory　drift　ratios　and　peak　floor　acceleration　demands　are　selected　as　critical　factors　to　build　single-　or　multiple-parameter　indices.　Based　on　the　relevant　performance　indices,　comparisons　between　the　original　and　upgraded　frames　show　that　the　overall　seismic　performance　of　MRFs　can　be　improved　by　10%-30%　when　SMA　braces　are　installed.　In　addition,　the　reduction　of　residual　deformation　has　a　significant　impact　on　the　evaluation　result　because　of　the　evident　benefit　to　seismic　performance.