To provide a rubber composition for tire rim cushion or gum finishing capable of enhancing the heat proof setting and the breaking strength without causing a reduction in hardness, and improving the driving stability as well as the durability.

Such a rubber composition for tire rim cushion or gum finishing is produced by blending 1 to 30 pts.mass of polyrotaxane compound having a cyclic molecule with blocked isocyanate group, a straight chain molecule enclosing the cyclic molecule in a skewer state and closing groups disposed at both ends of the straight chain molecule preventing the cyclic molecule from being detached from the straight chain molecule, and 70 to 90 pts.mass of carbon black whose nitrogen adsorption specific surface area (N₂SA) is 90 to 130 m²/g, into 100 pts.mass of rubber constituent comprising 40 to 60 pts.mass of natural rubber and 60 to 40 pts.mass of diene rubber having a modified group capable of reacting with isocyanate group.