To provide a curing accelerator which can be used as a substitute of N,N'-diphenyl guanidine in diene-based rubber composition containing silica, etc., which is a reinforcing filler for rubber, especially in rubber composition containing silica for a tire tread.

The rubber composition containing silica for tire tread comprising 100 pts.wt of a rubber component using diene-based rubber as a base, 30-70 pts.wt of silica as the reinforcing filler for rubber, 5-13 wt.% of silane coupling agent to the silica, 1.0-5.0 pts.wt of sulfur, 1.0-3.0 pts.wt of thiazole or sulfenamide-based curing accelerator and 0.02-0.3 pts.wt of tetrabenzyl thiuram disulfide.