The combination reaction of linear low density polyethylene initiated by Dicumyl peroxide at elevated temperature was investigated under different steady shear rates. Gel-permeation chromatography was used to determine the molecular weight distributions, and time-molecular weight superposition method was used to analyze the viscosity curves. The results showed that lower (or higher) shear rate increased the reaction possibility of shorter (or longer) chains. (c) 2006 Wiley Periodicals, Inc.