Abstract Ethene‐norbornene copolymerizations were conducted by (t‐BuNMe2SiFlu)TiMe2 (1) activated with dried methylaluminoxane (MAO) (free from Me3Al) at 0°C and 20°C under atmospheric pressure of ethene at various norbornene concentrations. At 0°C and high norbornene concentration, the molecular weight of the copolymer increased linearly against polymerization time while keeping narrow molecular‐weight distribution. The 13C NMR spectrum revealed that random copolymer with 53 mol‐% of norbornene was obtained. The glass transition temperature was above 150°C.