Abstract: Fushun-Bayuquan products pipeline was put into operation on Oct.28, 1995.The commissioning procedure of the pipeline was that water was first delivered, 4 hours later, gasoline was directly transported.During the batch transportation, a water-gasoline mixed section produced.The analytical results have shown that in fact this mixed section is only a blending of gasoline with water under the turbulent condition, not a real mixed contamination plug, which is absolutely different from the density variation (concen-trition) of mixed section of diesel/gasoline produced after pipeline commissions.In this paper, the axial spread of the gasoline turbulent flow central zone to the advancing water and the special variation of the mixed tail section are described.