Abstract: The behavior of mixed oil trailing exists in a refined oil batch transportation pipeline. Accordingly, when a constant-concentration cutting approach is used, forward refined oil possibly fails to meet the allowance for quality, and trailing refined oil may not be up to the quality standard once the delivery sequence changes. In this paper, the formation mechanism of mix oil trailing is discussed, and the evolution of mixed oil tail during the refined oil batch transportation is analyzed for PetroChina's West Products Pipeline. Then, through calculation, the mixed oil cutting approaches are proposed for Lanzhou Pump Station in the West Products Pipeline and Zhengzhou Pump Station in the Lanzhou-Zhengzhou-Changsha Products Pipeline. Moreover, it is suggested that different-concentration cutting approaches are adopted with the change of operating parameters like oil quality and flowrate, depending on delivery sequence, in other words, the cutting concentration of trailing refined oil when the mixed oil head is cut should be higher than the cutting concentration of forward oil in the mixed oil tail when the delivery sequence is opposite.