A　new　type　of　high　boron-high　speed　steel　(HB-HSS)　with　different　boron　content　was　selected　for　oil　quenching　at　1050　degrees　C,　and　different　temperature　of　tempering　treatment　was　chosen.　By　using　optical　microscopy,　scanning　electron　microscopy,　X-ray　diffraction,　Rockwell　hardness　tester,　red　hard　treatment　and　wear　test,　the　effects　of　heat　treatment　on　microstructure　and　properties　of　HB-HSS　were　investigated.　The　experimental　results　indicate　that　the　quenching　microstructure　of　HB-HSS　consists　of　-Fe,　M-2(B,　C),　M-7(B,　C)(3)　and　a　few　of　M-23(C,　B)(6).　When　the　tempering　temperature　is　lower　than　500　degrees　C,　the　shape　of　carboborides　will　change　from　discontinuous　sheet　to　continuous　net,　and　the　uniformity　in　microstructure　is　improved,　and　the　hardness　is　not　changed　during　the　process.　When　the　tempering　temperature　is　higher　than　500　degrees　C,　the　continuous　net　of　M-2(B,　C)　is　recovered.　When　the　tempering　temperature　is　higher　than　600　degrees　C,　the　microstructure　of　HB-HSS　get　thickened　because　of　overheating,　and　the　hardness　get　significantly　reduced.　With　the　increase　of　tempering　temperature,　the　weight　loss　of　the　sample　is　decreased,　and　the　wear　resistance　of　the　sample　is　increased.　When　tempering　temperature　exceeds　500　degrees　C,　the　weight　loss　of　the　sample　has　an　obvious　increase　and　its　wear　resistance　decreases.　The　wear　resistance　of　the　sample　decreases　after　the　red-hardness　treatment.　The　wear　loss　is　about　8.4mg　when　the　boron　content　is　2.0%　and　the　tempering　temperature　is　500　degrees　C,　which　is　the　best　of　test　samples.