An object of the present invention is to provide a cross-copolymer having excellent softness and heat resistance which is useful as a thermoplastic elastomer, and provide a method for producing thereof.The present invention provides a method for producing a cross-copolymer comprising a coordination polymerization step and an anionic polymerization step, the cross-copolymer has a specific structure. The present invention also provides a cross-copolymer having excellent moldability, softness and heat resistance, which can be produced under the producing conditions satisfying that the molecular weight distribution of the copolymer obtained in the coordination polymerization step is in a specific range.