The present invention aims to produce a rubber composition for a base tread, which suppresses reversion and achieves excellent mechanical strength, fuel economy and processability, and a tire using the rubber composition, with high efficiency to provide them to customers at low prices. The present invention relates to a rubber composition for a base tread, containing: a rubber component; and a mixture of a zinc salt of an aliphatic carboxylic acid and a zinc salt of an aromatic carboxylic acid, wherein the rubber component contains natural rubber and butadiene rubber, the butadiene rubber content being 10 to 90% by mass per 100% by mass of the rubber component, and the mixture of a zinc salt of an aliphatic carboxylic acid and a zinc salt of an aromatic carboxylic acid is contained in an amount of 1 to 10 parts by mass per 100 parts by mass of the rubber component.