Rubber composition and pneumatic tire using the same

A rubber composition comprising 5 to 60 parts by mass of a low-molecular weight aromatic vinyl compound-conjugated diene compound copolymer (B) having an aromatic vinyl compound content of 5 to 80% by mass, a vinyl bond content in a conjugated diene compound portion of 10 to 80% by mass and a weight average molecular weight as measured through a gel permeation chromatography and converted to polystyrene of 20,000 to 150,000 and 20 to 90 parts by mass of a filler (C) based on 100 parts by mass of a rubber component (A) composed of at least one of natural rubber and/or synthetic diene-based rubbers, in which the filler (C) comprises silica and carbon black, and 50 to 90% by mass of the filler (C) is silica,

• which further contains 5 to 15% by mass of a silane coupling agent (D) based on the amount of the silica compounded,
• wherein the low-molecular weight aromatic vinyl compound-conjugated diene compound copolymer (B) is an unmodified low-molecular weight aromatic vinyl compound-conjugated diene compound copolymer produced by polymerizing a mixture of conjugated diene compound and aromatic vinyl compound in a hydrocarbon solvent.