To obtain a rubber composition for inner liners having sufficiently low air permeability.

This rubber composition for the inner liners comprises muscovite having ≥40 μm average particle diameter in an amount of 3-20 pts.wt. based on 100 pts. wt. of a rubber component containing 50-100 wt.% of butyl rubber or the muscovite having the surface coated with a resin in an amount of 3-20 pts.wt. based on 100 pts.wt. of the rubber component and a plasticizer in an amount of ≥5 pts.wt. based on 100 pts.wt. of the rubber component. The resin is preferably selected from the group consisting of a urethane resin, an acrylic resin and an epoxy resin.