RUBBER COMPOSITION AND PNEUMATIC TIRE

A rubber composition comprising a diene-based rubber, a filler, an oil, and water-soluble cellulose. It is preferrable that the rubber composition comprises 1 to 25 parts by mass of the water-soluble cellulose per 100 parts by mass of the diene-based rubber. It is preferrable that the water-soluble cellulose is one in which at least a part of hydrogen atoms of hydroxyl groups of cellulose is substituted with at least one substituent selected from the group consisting of a carboxyalkyl group and a hydroxyalkyl group. It is preferrable that the water-soluble cellulose in the state of a 1% aqueous solution at 23° C. has a viscosity of 5,000 to 15,000 mPa·s.