The　effects　of　Nb　addition　on　the　crystallization　kinetics,　microstructure　and　magnetic　properties　of　melt-spun　Nd2Fe14B/α-Fe　nanocomposite　magnets　have　been　studied.　The　analysis　of　crystallization　kinetics　for　the　alloys　indicates　that　the　growth　of　crystallites　in　the　Nb-doped　alloy　needs　more　activation　energy　than　that　in　the　Nb-free　alloy.　This　crystallization　behaviour　contributes　to　the　formation　of　a　finer　and　more　homogeneous　microstructure　in　the　Nb-doped　alloy　than　in　the　Nb-free　alloy.　And　the　Nb　addition　makes　the　grains　more　equiaxed　shape.　The　intrinsic　coercivity　and　the　maximum　energy　product　increase　from　600　kA/m,　105　kJ/m3　for　Nd10Fe84B6　alloy　to　750　kA/m,　120　kJ/m　3　for　Nd10Fe83Nb1B6　alloy,　respectively.　©　Published　under　licence　by　IOP　Publishing　Ltd.