(Nd1-xLax)(30)Fe69B　(x=0,　0.1,　0.2,　0.3,　0.4,　0.5,　0.6)　alloys　were　prepared　by　inducting　melting,　and　the　effect　of　substitution　of　La　for　Nd　on　their　microstructure　and　intrinsic　magnetic　properties　were　investigated.　With　the　increase　of　La　content,　Curie　temperature　(T-c)　decreased　from　582.4　to　557.4K,　saturation　magnetization　(M-s)　decreased　from　1.59　to　1.37　T,　and　anisotropy　field　(H-A)　decreased　from　5394　to　3911　kA/m.　However,　the　reductions　of　the　intrinsic　magnetic　properties　were　relatively　gentle　as　La　content　increased,　which　meant　that　the　intrinsic　magnetic　properties　still　had　the　potential　to　fabricate　permanent　magnets.　Moreover,　further　microstructure　observations　showed　that　La　tended　to　diffuse　into　the　Nd-rich　grain　boundary　phase　instead　of　main　phase　during　the　substitute　process.　Such　aggregation　behavior　was　beneficial　to　fabricating　La　containing　magnet　with　high　M-s.