Abstract: On the basis of defining the structural background and the distribution of sedimentary system in Shulu sag, by combing the oil and gas accumulation conditions, reservoir types and distribution regularities of the western slope, the reservoir forming patterns of different types of reservoirs are determined. The results show that from the direction of North to South, the reservoir distribution of western slope in Shulu sag is mainly concentrated in Nanxiaochen structural belt in the north, the Xicaogu-Taijiazhuang structural belt in the central and southern parts and the Leijiazhuang structural belt in the south. Among them, the XicaoguTaijiazhuang structural belt is adjacent to the central sag, with sufficient oil and gas supply, and has the advantage of continuous accumulation. From the direction of East to West, the reservoir is mainly distributed in the inner zone of the western slope, while the outer zone of the western slope has a small scale. There are mainly four types of oil and gas reservoirs: lithologic, structural, stratigraphic and composite in the western slope zone of Shulu sag. The types and patterns of oil and gas reservoirs developed in different parts of the slope belt are different. Structural reservoirs are mainly developed in the inner zone of the slope, while stratigraphic reservoirs are mainly developed in the outer zone of the slope. As for the western slope, there are mainly stratigraphic and lithologic reservoirs in the south, structural reservoirs, lithologic reservoirs and structural lithologic composite reservoirs in the middle, structural reservoirs and buried hill reservoirs in the north.