To provide a silica-filled diene-based rubber composition that is suitably used as a vulcanization molding material for a tread part of a pneumatic tire or the like, increases a vulcanization rate and can give a vulcanized product having an excellent balance of viscoelastic properties.

A diene rubber composition comprising diene rubber, silica, a silane coupling agent and a tetrazole derivative represented by the formula (wherein n is an integer of 4-10) achieves the object. The diene rubber composition comprises 20-100 pts.wt. silica per 100 pts.wt. diene rubber and the silane coupling agent and the tetrazole derivative each in an amount of 2-15 wt.% based on the weight of silica.