Polyethylene with broad molecular weight distribution can be obtained by using catalytic systems consisting of two or more catalyst components．An asymmetrically bridged metallocene compound [(CH3)2C(η-C5H4)(η-C9H6

)]ZrCl2 and different unbridged metallocene compounds(＼／Cp)2ZrCl2

(Cp)2ZrCl2 and (CP)2ZrCl2 were used to constitute three catalytic systems cocatalyzed with MAO for ethylene oolymerization．Polyethylene with short chain branch and broad molecular weight distribution was obtained．By changing the molar ratio of two-component metallocene catalysts and polymerization temperature

the activity of the ethylene polymerization and the molecular weight and molecular weight distribution of the resultant polyethylene were investigated．The molecular weight and molecular weight distribution of polyethylene were determined by viscometry and GPC．The melt point and crystailinity of polyethylene samples were determined by DSC．The results showed that the molar ratio and polymerization temperature had important effect on the activity and molecular weight．The results indicated that it was possible to tailor molecular weight and molecular weight distribution by changing the molar ratio of the two-component metallocene catalysts and polymerization temperature in ethylene polymerization with two-component metallocene catalyst systems．