RUBBER COMPOSITION AND PNEUMATIC TIRE USING SAME

An object of the present invention is to provide a rubber composition capable of achieving both excellent vulcanization properties as low heat build-up, and a pneumatic tire including such a composition. The rubber composition of the present invention is a rubber composition containing a diene rubber (A), a silica (B), a silane coupling agent (C), and an acid-modified polyolefin (D); the diene rubber (A) containing not less than 30 mass% of an aromatic vinyl-conjugated diene copolymer rubber; the acid-modified polyolefin (D) having at least one type of repeating unit selected from the group consisting of propylene, 1-butene, and 1-octene; a content of the silica (B) being from 5 to 150 parts by mass per 100 parts by mass of the diene rubber (A); and a total content of the silane coupling agent (C) and the acid-modified polyolefin being from 5 to 30 parts by mass per 100 parts by mass of the diene rubber (A).