Copolymerization of ethylene with styrene using linked cyclopentadienyl-amide titanium(IV) complexes, [Me2Si(C5Me4) (R)]TiCl2 [R = tert-Bu (1), cyclohexyl (2)], and non-bridged (1,3-Me2C5H3)TiCl2(O-2,6-(i) Pr2C6H3) (3)-MAO catalysts have been explored. Although the catalytic activity by 2 was lower than 1, 2 showed more efficient styrene incorporation than 1 under the same conditions. Moreover, the resultant copolymer prepared by 2 possessed completely different microstructure from those by 1, indicating that the nature of amide ligand affects both styrene incorporation and monomer sequence. (C) 2002 Elsevier Science B.V. All rights reserved.