ving a vinyl bonding rate of not more than 20%, and polymer unit (E) is a conjugated diene polymer or an aromatic vinyl compound-conjugated diene copolymer wherein the vinyl bonding rate is in the range of 30-90% and p is an integer of more than 1, and said fourth block copolymer being composed of said polymer units (D) and (E) of said third block copolymer, and further containing a coupling agent