To provide a method for preparing a cyclic olefin copolymer which does not produce oxidatively deteriorated components from the cyclic olefin, and excels in polymerization activity, has high efficiency of copolymerization of the cyclic olefin, and furthermore excels in stereoselectivity and randomness.

The method for preparing a cyclic olefin copolymer comprises copolymerizing an α-olefin and a cyclic olefin in the presence of a compound represented by formula (1) and a compound represented by formula (2) as catalysts.