To provide a diene-based rubber composition which is suitable for use as a vulcanization molding material for forming a cap tread part of a fuel-efficient tire or the like by improving breaking elongation, rolling resistance and abrasion resistance in a well-balanced state.

The diene-based rubber composition includes, based on 100 pts.wt. of diene-based rubber, 20 pts.wt, or more of carbon black having CTAB specific surface area (based on JIS K6217-3) of 110-180 m2/g; 0.2-5.0 pts.wt. of polyether polyol represented by the general formula, wherein l, m and n are each independently an integer of 2-10; 5-50 pts.wt. of pulverized bituminous coal; and 10-100 pts.wt. of silica having CTAB specific surface area (based on JIS K6217-3) of 95-175 m2/g, the total mixing quantity of the carbon black, the pulverized bituminous coal and the silica being 35-150 pts.wt.