A rubber composition of the invention comprises [1] a cross inked rubber particle component whose toluene-insolubles is 50% by weight or more and whose number mean particle size is 3 to 1000 nm and [2] a non-crosslinked rubber component whose toluene-insolubles is less than 20% by weight. This crosslinked rubber particle component is a polymer comprising at least one selected from (1) a conjugated diene unit, (2) a conjugated diene unit and an &agr;,&bgr;-unsaturated nitrile unit and (3) a conjugated diene unit and an acrylate unit as well as a monomer unit having at least 2 polymerizable unsaturated groups. The non-crosslinked rubber component described above is a polymer co rising at least one selected from (a) a conjugated diene unit, (b) (a) plus an aromatic vinyl unit, (c) (a) plus an &agr;,&bgr;-unsaturated nitrile unit, (d) (a) plus an acrylate unit and (e) an ethylene unit and an &agr;-olefin unit having 3 to 12 carbon atoms.