A rubber composition for use in a tire tread includes: per 100 parts by weight of diene rubber containing 40 wt % or greater of butadiene rubber, and a styrene butadiene rubber, from 80 to 150 parts by weight of silica having a CTAB specific surface area of 150 to 250 m2/g, and a long chain alkyl group-containing silane compound in an amount of 1 to 10 wt % of the amount of the silica. The rubber composition further includes a styrene component in the diene rubber being from 15 to 20 wt %, and a vinyl component in the diene rubber being from 18 to 28 wt %; and an average glass transition temperature of the diene rubber is −55° C. or lower.