Abstract: Weibei Oilfield is one of new oil-bearing blocks in southern Ordos Basin in the recent two years.Taking 3₃ Oil Formation of the fourth member of Yanchang Formation in dense well area as the example,based on various data including cores,well logging and production performance,internal configuration of underwater distributary channel sand of braided river delta is studied in this paper.Under the premise of the basic characteristics of single channel in single well,using the method of well-seismic tie in profile and the combination of the maximum thickness of single sand body and number of the sand bodies in each small layer in plane,eight single channel development periods have been identified in Chang3₃ Oil Formation;the number and distribution of single channels in complex channels have been identified in plane as while;besides,four kinds of sand bodies superimposition models and their distribution were summarized including incised superimposition model,in-completed incised superimposition model,isolated model and thin-layer superimposition model,which provides geological basis for waterflooding in dense well area and the selection of future favorable area in its adjacent region.