A　new　kind　of　automobile　brake　composites　reinforced　by　magnesium　hydroxide　sulfate　whisker　(M-HOS)　and　prepared　by　molding　compression　has　been　developed.　The　sliding　friction　and　wear　properties　of　the　brake　composites　were　investigated.　The　sliding　experiments　were　carried　out　on　a　model　JF150D-II　pin-on-disc　tribometer.　The　contact　configuration　used　was　a　stationary　specimen　on　a　rotating　HT250　cast　iron　flat.　The　results　indicate　that　the　brake　composites　show　excellent　friction　stability　at　different　temperatures,　low　wear　rate　and　good　thermal　fade　resistance.　As　test　temperatures　increased　from　100°C　to　350°C,　the　average　friction　coefficient　is　0.39　with　the　maximum　fluctuation　of　0.08.　The　ratio　of　the　friction　coefficient　at　350°C　versus　the　maximal　friction　coefficient,　(f350/fmax),　is　0.95.　The　integrant　specific　wear　rate　is　lower　and　keeps　to　0.89×10-7cm3/(N·m)　at　350°C.