Abstract: Flow properties of a waxy crude are influenced by shear history.The cross-sectional average shear rate or the shear rate at the pipe wall in turbulent flow was unreasonably used to evaluate shear history in pipe flow.According to the relationship between the shear rate and the energy dissipation rate,a method for calculating the average shear rate based on the volumetrically average energy dissipation rate is presented.This method may be easily used to calculate the average shear rate in pipe flow of the Newtonian and the power law fluids according to the fluid density,average velocity,pipe diameter,the frictional factor or frictional pressure drop,and the rheological parameters.The average shear rate obtained with this method is a more reasonable measurement of the average shear history of fluid in turbulent pipe flow.Within the range of the Reynolds number commonly encountered in crude oil pipelines,the cross-sectional average shear rate of pipeflow is less by 20%~40% than that calculated by using the presented method.