Copolymerization of ethylene and cyclopentene (CPE) was carried out with various non‐bridged and bridged zirconocene catalysts using methylaluminoxane as a cocatalyst. Non‐bridged metallocene catalysts effected ethylene homopolymerization without copolymerization. On the other hand, bridged zirconocene catalysts produced copolymers containing cis‐1,2‐cyclopentane units. Among the used catalysts, rac‐ethylenebis(indenyl)zirconium dichloride [Et(Ind)₂ZrCl₂] gave copolymers containing the highest amount of CPE units by 1,2‐insertion or 1,3‐insertion. Temperature‐rising elution fractionation of the copolymers using 1,2‐dichlorobenzene as a solvent showed a broad distribution of copolymer composition in copolymers obtained by specific zirconocene catalysts.