The　critical　points　and　time-temperature-transformation　(TTT)　curves　of　the　isothermal　transformation　diagrams　for　a　high-speed　steel　casting　on　a　horizontal　centrifugal　casting　machine　had　been　determined　experimentally　in　the　study.　The　effects　of　quenching　temperature　on　the　microstructures　and　properties　of　centrifugal　casting　high　speed　steel　(HSS)　roll　has　been　investigated　using　scanning　electron　microscopy　(SEM),　light　optical　microscopy　(LOM)　and　X-ray　diffraction　(XRD)　as　well　as　using　tensile,　impact,　and　hardness　tests.　The　results　show　that　the　HSS　roll　has　excellent　hardenability　and　its　matrix　structure　can　be　transformed　into　the　martensite　after　being　quenched　in　the　sodium　silicate　solution.　The　retained　austenite　in　the　quenching　structure　increases　and　the　hardness　decreases　when　the　quenching　temperature　exceeds　1,040　degrees　C.　The　tensile　strength　and　impact　toughness　of　HSS　roll　increase　once　the　quenching　temperature　is　raised　from　980　degrees　C　to　1,040　degrees　C.　However,　the　tensile　strength　and　impact　toughness　have　no　significant　change　when　the　quenching　temperature　exceeds　1,040　degrees　c.　The　HSS　roll　quenched　at　1,040　degrees　C　exhibits　excellent　comprehensive　mechanical　properties.