Microstructure　modification　induced　giant　coercivity　enhancement　from　950　to　1688　kA/m　has　been　achieved　in　Sm(Co0.665Fe0.25Cu0.06Zr0.025)(7)　permanent　magnets　via　Cu　powders　doping.　Microstructure　observation　shows　that　in　original　magnet　there　are　Cu-lean　regions　along　the　grain　boundary　area,　where　regular　cellular　structure　does　not　form.　After　Cu　powders　doping,　most　Cu-lean　regions　disappear.　Comparison　of　magnetic　domain　reversal　between　the　original　magnet　and　doped　magnet　indicates　that　reversed　domain　propagation　was　substantially　restrained　due　to　the　elimination　of　the　Cu-lean　region.　Moreover,　the　pinning　field　increases　by　83.3%　after　Cu　doping,　having　good　agreement　with　coercivity　enhancement.　(C)　2017　Acts　Materialia　Inc.　Published　by　Elsevier　Ltd.　All　rights　reserved.