This invention relates to a rubber composition capable of improving wear resistance without losing low heat buildup and a heavy duty pneumatic tire in which the low heat buildup and the wear resistance are simultaneously established, and more particularly to a rubber composition characterized by comprising 40 to 60 parts by mass of a carbon black based on 100 parts by mass of a rubber component composed of natural rubber and a diene-based synthetic rubber and satisfying a relation of the following formula (1):ΔE′<0.29×A−11 (1)[wherein ΔE′ is a difference between a storage modulus (MPa) at a strain of 0.1% and a storage modulus (MPa) at a strain of 2% measured at 25° C., and A is an amount (parts by mass) of the carbon black compounded based on 100 parts by mass of the rubber component] and a heavy duty pneumatic tire characterized by using the rubber composition in a tread.