Abstract: In order to explore delta front reservoir architecture features and the remaining oil distribution,due to the strong reservoir heterogeneity and the complex characteristics of remaining oil distribution on Bai 157 well block of Baibao oilfield in Ordos basin,by making full use of cores,well logging and production data,thorough the research on the reservoir internal architecture,the types and characteristics of delta front reservoir architecture elements were clearly introduced.Boundaries of a single sand body has four recognition methods and the superimposed pattern on the vertical and lateral configuration elements were put forward.In vertical direction,it was mainly divided into erosion type,overlapping and isolation type.In side direction,it could be divided into two types,namely lateral tangential type and lateral separated type.The residual oil enrichment of different configurational elements was different,and there were three models of distribution of remaining oil in anti-metrical estuarine dike body,top,middle and bottom models.While in the normal rhythm of the underwater distributary channel,the remaining oil was generally concentrated in the upper part of the middle.