The　nanocrystalline　Sm5Co19　based　alloys　were　firstly　prepared,　with　Fe,　Ni　and　Nb　as　doping　elements.　The　microstructure,　crystal　structure　and　magnetic　properties　at　room　temperature　and　high　temperatures　were　studied　for　the　nanocrystalline　alloys,　and　the　effects　of　doping　elements　on　the　microstructure　and　magnetic　performance　were　analyzed.　It　was　found　that　Ni,　Fe　and　Nb　doping　facilitated　transformation　from　rhombohedral　to　hexagonal　structure　of　the　nanocrystalline　Sm5Co19　based　alloys.　The　nanoparticles　with　the　hexagonal　structure　enhance　the　coercivity　of　the　nanocrystalline　alloys.　At　high　temperatures,　as　compared　with　the　binary　Sm5Co19　alloys,　the　dispersed　nanoparticles　containing　Fe　and　Ni　increase　both　the　coercivity　and　saturated　magnization,　from　which　good　high-temperature　magnetic　performance　of　the　nanocrystalline　Sm5Co19　based　alloys　were　obtained.　The　results　may　facilitate　development　of　new　type　Sm-Co　alloys　with　high　magnetocrystalline　anisotropy　and　good　high-temperature　magnetic　performance.　(C)　2017　Elsevier　B.V.　All　rights　reserved.