To provide a rubber having a reinforcing agent of a starch, and a tire including the same as a component.

This rubber composition comprises (A) 100 pts.wt. of a elastomer based on at least one kind of a diene, (B) 0.1-120 phr of at least one kind of an elastomer-reinforcing filler comprising (1) 0.1-120 phr of a material based on at least one kind of a starch selected from at least one kind of the starch, a composite material of the starch and a plasticizer, and a modified starch, and (2) 0-90 phr of a carbon black or an amorphous silica, (C) optionally a coupling agent for the material based on the starch and the material based on the silica when the silica is used, and (D) at least one kind of methylene acceptor compound and/or methylene donor compound (except hexamethylenetetramine).