Copolymerization of ethylene/1 octene with three ansa zirconocene/MAO catalyst systems were investigated. The polymerization activity is dependent upon the influence of electronic effects. It decreases in the following order: C6H4(CH2)2Cp2ZrCl2> C5H3N(CH2)2Cp2ZrCl2 > CH3N(CH2)2ZrCl2. The composition and sequence distribution of copolymer were calculated from 13 C NMR spectra. It was found that the activityes of three ansacatalysts were lower than Et(Ind) 2ZrCl2 under the same 1-octeone concentration.And their copolymer had lower 1-octene incorporation than that of Et(Ind)2ZrCl2 under the same 1-octeone concentration.And their copolymer and lower 1-octene incorporation than that of Er(Ind)2ZrCl2.Other properties such as molecular wieght

melting point of copolymer were compared.