Lixian Slope is a large wide-gentle slope in the western part of Raoyang Sag, Jizhong Depression, Bohai Bay Basin. It is characterized by low gradient in the tendency and relatively obvious palaeotopographic differences in the trend, and it is constituted of different terrain units such as platform and monocline areas from north to south. Based on observation of cores and analysis on individual well facies and logging facies, and combining with numerous test data such as granularity, petrology and mineral analyses, etc, two different sedimentary facies, including “shallow water” delta, sand bar and beach of shallow-shore lacustrine, are recognised, which constituted the main reservoir of the Member 2 and the Lower part of Member 1 of Shahejie Formation of Paleogene in the study area. According to the differences of basic elements including sedimentary facies types and palaeogeomorphology in the trend, two different types of sandbody concentrating areas are classified in the study area, respectively named as delta facies sandbody concentrating area of monocline slope terrain unit and sand bar and beach facies sandbody concentrating area of platform terrain unit from south to north of the Lixian Slope. However, the forming conditions of subtle petroleum reservoir are different. It is suggested that the concentrating areas of sand bar and beach facies sandbodies of platform terrain unit are the favorable areas for searching subtle petroleum reservoir. Whereas compared to the sand bar and beach facies sandbody concentrating area of platform terrain unit, the exploration potential of the delta facies sandbody concentrating area of monocline slope terrain unit is relatively poor. On the other hand, the models of subtle petroleum reservoir are different on the inner, middle and upper belts of Lixian Slope. In general, the middle belt of the slope distributes a variety types of subtle petroleum reservoir which consist of sandstone updip pinch-out, lenticle lithologic oil reservoir and structural-lithologic oil reservoir. Vertically and laterally, these types of subtle petroleum reservoir overlaped each other and their oil-bearing beds were widespread on the middle belt of the slope, so the middle belt of the slop is considered as a main target area for subtle petroleum reservoir exploration.