To provide a rubber composition having a faster vulcanization speed and enhancing aging resistance by solving the problem that the vulcanization speed becomes slow when a cyclic polysulfide is used although it has been known that cyclic polysulfides are used as a crosslinking agent in order to improve aging resistance of rubber, and a pneumatic tire using it.

The rubber composition includes 1-6 pts.mass of a cyclic polysulfide, 0.5-12 pts.mass of zinc carboxylate, 0-2 pts.mass of zinc oxide and 100 pts.mass of the diene-based rubber. In the pneumatic tire, the rubber composition is used.