Most mature onshore oilfields in China have entered the high water-cut stage，and the field experience shows that some oil wells have a lower water cut after a certain shut-in period，the reason for which is the remaining oil re-enrichment. The remaining oil re-enrichment in the lower potential closed zones after water flooding under the effect of gravity and capillary force is one of the important factors affecting the of remaining oil re-distribution. In this paper，the water saturation classification standard for waterflooded reservoirs was established by means of the water cut classification and fractional flow curve. On this basis，the indexes for the re-enrichment and the potential producing of remaining oil were constructed to characterize and evaluate the remaining oil re-enrichment. Based on the laboratory-scale physical simulation experiment，The influence of different factors on remaining oil re-enrichment was simulated separately under the dominant conditions of gravity or hydrodynamics. The results show that the remaining oil re-enrichment mainly occurs in the upper part of a reservoir and the lower part of the interlayer under the dominant condition of gravity，and the re-enrichment effect is better at a high-pressure gradient. Under the dominant condition of hydrodynamics，the high-pressure gradient can promote the remaining oil re-enrichment，and a farther distance from well pattern to the top of the structure indicates a larger space for remaining oil re-enrichment and higher recovery.