Influences　of　the　tempering　temperature　on　the　microstructure,　mechanical　property　and　wear　resistance　of　High-Boron　High　Speed　Steel　(HBHSS)　roll　materials　were　investigated　by　means　of　optical　microscopy,　scanning　electron　microscopy　(SEM),　X-ray　diffraction,　hardness　measurement,　impact　tester,　tensile　tester　and　pin　abrasion　tester.　The　results　show　that　the　as-cast　structure　of　HBHSS　consists　of　a　great　amount　of　martensite　and　M-2(B,C)　and　a　few　retained　austenites　and　M-23(B,C)(6).　After　solution　treated　at　1,050　degrees　C　and　followed　by　oil　cooling,　the　amount　of　M-23(B,C)(6)　carbo-borides　in　quenched　HBHSS　increases　obviously　and　the　macrohardness　of　the　quenched　HBHSS　is　66　HRC,　which　is　very　close　to　the　65.8　HRC　of　as-cast　HBHSS.　On　the　whole,　the　hardness　of　HBHSS　alloy　shows　a　trend　of　slight　decrease　with　increasing　tempering　temperature　when　tempered　below　500　degrees　C.　While　when　above　500　degrees　C,　the　hardness　increases　slightly　as　the　tempering　temperature　increases　and　reaches　a　peak　at　525　degrees　C　and　then　decreases　obviously.　The　impact　toughness　of　HBHSS　has　a　tendency　to　increase　as　the　tempering　temperature　increases.　Tempering　can　improve　the　tensile　strength　and　elongation　of　HBHSS,　but　a　higher　tempering　temperature　causes　a　slight　decrease　in　both　tensile　strength　and　elongation.　Excellent　wear　resistance　can　be　obtained　by　tempering　at　500　to　550　degrees　C.