The object of the present invention is to provide a rubber composition for base tread enhancing a low fuel consumption property of a vehicle. A rubber composition for base tread comprises a rubber composition containing 15 to 80% by weight of a butadiene rubber obtained by copolymerizing a compound represented by the formula 1, ##STR00001## wherein R.sup.1 represents an amino group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group, a mercapto group or a derivative thereof.