The　bulk　nanocrystalline　Nd-Fe-B　magnets　in　cylindrical　form　with　various　diameters　were　prepared　by　injection　casting　of　the　molten　alloy　into　copper　moulds.　The　effects　of　the　diameter　size　and　the　application　of　magnetic　field　during　the　solidification　process　on　the　magnetic　properties　and　microstructure　of　Nd9.5Fe71.5Ti2.5Zr0.5Cr1B14.5C0.5　alloy　have　been　studied.　The　smaller　the　diameter　is,　the　better　magnetic　properties　can　be　obtained.　The　intrinsic　coercivity　of　bulk　magnet　is　more　sensitive　to　the　diameter　size　than　the　remanence.　Applying　a　3.0　kOe　magnetic　field　during　the　casting　process　is　helpful　to　refine　the　grain　size,　thus　improving　the　magnetic　properties　of　bulk　magnets,　especially　the　intrinsic　coercivity.　The　increase　in　the　intrinsic　coercivity　induced　by　the　applied　magnetic　field　is　much　obvious　for　the　samples　with　larger　size.