The rheological property of metallocene polyethylene MPE(ethylene and 1-butene copolymer) and conventional LDPE has been studied in detail by using a Rheometrics Scientifics DSR-200 rheometer with parallel plate geometry. Measurements include steady-state viscosity

dynamic viscoelasticity

followed by linear fitted with the modified cross model.MPE has poor processability due to its narrow MWD. Compared with conventional LDPE

MPE has higher apparent viscosity in middle shear rate range

low sensitivity to shearing

and higher values of shear rate and shear stress in the transition region from Newtonian to power-law behavior. In order to improve its processability

MMPE modified from MPE has been produced. MMPE has all the advantages of metallocene polyethylene

and also has good processability:lower apparent viscosity

higher sensitivity to shearing

and lower values of shear rate and shear stress in the transition region from Newtonian to power-law behavior.The blown film with good mechanical properties has been made from MMPE.