A rubber composition having satisfactory processability and dimension stability, exhibits excellent tensile strength and wearing resistance when vulcanized and comprises (1) a crosslinked rubber particle containing as repeating units (a) 39.89 to 79.89% by weight of a conjugated diene unit such as 1,3-butadiene or the like, (b) 20 to 60% by weight of an aromatic vinyl unit such as styrene, (c) 0.01 to 10% by weight of a monomer unit having at least two polymerizable unsaturated group such as divinylbenzene, and the like, and (d) 0.1 to 30% by weight of a monomer unit having one polymerizable unsaturated group and an amino group such as vinylbenzylmethylamine, and the like and (2) a conjugated diene/aromatic vinyl copolymeric rubber such as styrene-butadiene copolymeric rubber and the like.