Rubber-modified　Portland　cement　Concrete　(RMC)　was　made　by　using　small　rubber　particles　from　waste　tires　to　replace　some　portions　of　natural　sand.　The　added　rubber　particles　reduce　the　strength　of　RMC,　which　greatly　limits　the　applications　of　RMC.　Several　methods　were　used　in　this　study　to　improve　mechanical　properties　of　RMC,　such　as　lower　water-cement　ratio　(W/C),　the　addition　of　silica　fame,　and　the　pretreatment　of　rubber　particles　by　coupling　agents,　PVA　and　silane.　Test　results　showed　that　a　low　W/C　ratio　significantly　increases　the　strength　of　RMM(rubber　modified　mortar).　Both　PVA　and　silane　are　very　effective　in　improving　the　compressive　strength　of　RMM.　The　compressive　strength　of　RMM　can　be　further　improved　by　using　a　combination　of　methods　such　as　having　a　low　W/C　ratio　and　pretreatment　of　rubber　surface　by　a　coupling　agent.　Although　the　strength　of　RMC　decreased,　the　toughness　and　fatigue　resistance　obviously　increased.　The　microstructure　of　RMC　were　analyzed　by　SEM,　and　the　SEM　results　showed　that　the　interfaces　between　rubber　particles　and　cement　paste　matrix　are　improved　significantly　by　using　the　pretreatments　of　silane　and　PVA.