To provide a rubber composition for a tire which attains both enhancement of wet grip performances and low rolling resistance and can improve processability.

The rubber composition comprises 100 pts.wt. of a diene rubber containing a styrene butadiene rubber having a specific coupling ratio and specific Mooney viscosity and bearing at a polymer end a functional group reactive with a silanol group, 40-120 pts.wt. of silica having a specific CTAB specific surface area and a specific DBP oil absorption and 1-20 pts.wt. of a silane coupling agent represented by the general formula: (RO)3-Si-(CH2)xSn(CH2)x-Si-(OR)3, where the ratio of silica in the reinforcing filler is at least 60 wt%, the ratio of the silane coupling agent having n of 2 in the general formula is at least 60 wt%, and the average linkage of S is 2-3. The rubber composition for the tread is obtained by kneading the base rubber at a certain kneading temperature.

COPYRIGHT: (C)2005,JPO&NCIPI