PURPOSE:To obtain a rubber composition capable of effectively preventing ozone deterioration in low-temperature area and having excellent appearance by blending a diene-based rubber with a specific petroleum paraffin at a pre scribed ratio. CONSTITUTION:The objective rubber composition obtained by blending (A) 100 pts.wt. diene-based rubber with (B) 1-10 pts.wt. paraffin wax containing 3-8wt.% 23-30C, straight-chain saturated hydrocarbon, >=2wt.% 31-44C straight- chain saturated hydrocarbon and 23-30C straight-chain saturated hydrocarbon of arithmetic mean weight content 1% higher than that of 31-44C straight-chain saturated hydrocarbon.