METHOD FOR PRODUCING BLOCK COPOLYMER

PROBLEM TO BE SOLVED : To provide a method for producing a block copolymer of a conjugated diene and a polar monomer. SOLUTION : This method for producing the block copolymer of the conjugated diene and the polar monomer comprises the homopolymerization of the conjugated diene in the presence of a catalyst composition containing (A) a metallocene complex of a rare earth metal compound and (B) an ionic compound composed of a non-coordinating anion and cation and/or an aluminoxane and the addition of the polar monomer to the homopolymerization product.