A series of nature rubber(NR) composites based on carbon black,silica,and active calcium silicate modified by silane agents were prepared by melt blending.The effect of modification agenttypes and quantity,powder supply rate,filler combination on the mechanical properties of the rubbercomposites were researched.The vulcanizing torque and curing time were obviously reduced comparedwith rubbers with silica or carbon black.The tensile strength and tear strength of rubber with activecalcium silicate decreased compared with the pure rubber.But the tensile strength at 100% and 300% of NR composites filled by 50 portion active calcium silicate equivalent to composites filled by 50 portion carbon black.