Abstract: The friction drag characteristics is analyzed for the crude oil which has the behavior of psuedo-plastic fluid, when the crude oil transported in heat pipe. The concept and calculations are proposed for the critical effective shear rate of pipe flow that the friction loss of non-Newtonian crude oil is decreased as the transporting temperature is declined. For the Newtonian fluid, the increment magnitude of friction loss of non-Newtonian fluid is decreased as flow rate is increased, and the less the rheological index of oil is, the more the trend is; for the hot oil pipeline transporting the crude oil of non-Newtonian fluid, the shear rate has only relations to the behavior of the crude oil to be transported.