RUBBER COMPOSITION AND PNEUMATIC TIRE

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[Subject Matter] To provide a rubber composition capable of making well- balanced improvements to wet grip performance, wear resistance and tensile strength, and to provide a pneumatic tire having a tread produced by using the rubber composition. [Solution(s)] A rubber composition, containing a rubber component made of an oil-extended butadiene rubber having a cis content of 95 mol% or greater, a vinyl content of 1.2 mol% or less and a weight-average molecular weight of 530, 000 or greater, and/or a styrene-butadiene rubber having a bound styrene content of 10∼60 mass% and a weight-average molecular weight of 800, 000 or greater; an inorganic reinforcement agent represented by the formula below and having a nitrogen adsorption specific surface area of 10∼60 m2/g or greater; and silica having a nitrogen adsorption specific surface area of 100 m2/g or greater and/or carbon black having a nitrogen adsorption specific surface area of 100 m2/g or greater. To produce such a rubber composition, the oil-extended butadiene rubber is synthesized using a rare-earth element-based catalyst, the total content of the oil-extended butadiene rubber and the styrene-butadiene rubber is 10∼100 mass% of the rubber component, and based on 100 parts by mass of the rubber component, the content of the inorganic reinforcement agent is 1∼70 parts by mass and the total content of the silica and carbon black is at least 50 parts by mass.          mM·xSiOy·zH2O (in the formula, "M" represents at least one metal selected from the group consisting of Al, Mg, Ti, Ca, Zr, an oxide of the metal thereof and a hydroxide of the metal thereof, "m" is a whole number of 1∼5, "x" is a whole number of 0∼10, "y" is a whole number of 2∼5, and "z" is a whole number of 0∼10)