A NEW RUBBER COMPOSITION COMPRISING RUBBER REINFORCED BY DISTRIBUTING THEREIN CARBON FIBERS, CARBON BLACK AND SOFTENED IN COMBINATION RESPECTIVELY IN A PARTICULAR AMOUNT. THE SUITABLE AMOUNTS ARE 0.02 TO 0.10 VOLUME FRACTION OF CARBON FIBERS, 0.05 TO 0.25 VOLUME FRACTION OF CARBON BLACK AND 0.02 TO 0.30 VOLUME FRACTION OF SOFTENER. SUBSTANTIALLY UNIFORMLY DISTRIBUTED CARBON FIBERS, CARBON BLACK FINE PARTICLES AND FURTHER FINER SOFTENER PARTICLES DISPERSE THE CONCENTRATED STRAIN LOCALLY GENERATED IN THE RUBBER COMPOSITION TO EFFECTIVELY PREVENT THE SUDDEN DETERIORATION OF THE RUBBER ARTICLE WHICH PHENOMENON CAN BE OBSERVED IN SOME TYPES OF RUBBER. THUS THE VULCANIZED RUBBERS MADE OF SAID COMPOSITION HAVE HIGH RESISTANCE OF FATIGUE, ELONGATION, MECHANICAL STRENGTH AND ELASTICITY IN COMBINATION WHICH MAKES THEM VERY USEFUL FOR TIRES, CONVEYOR BELTS ETC. TO BE SUBJECTED TO SEVERE DYNAMIC CONDITIONS.