The distribution of hydrocarbon resources in the paleogene strata in Tanhai area, the Jiyang Depression, Bohai Bay Basin, is affected by the development characteristics of fault network. In this paper, we hope to define the plane geometric features of the fault network and establish the relationship between the geometric features of the fault network and the oil and gas distribution.Methods:Based on structural interpretation of seismic data, fractal and topological methods are used to analyze the development characteristics of the fault network on the plane.Results:On the T6 interface, the high value area of fractal dimension and topologicalvalue spread out in NW, with the characteristics of high in south and low in north; At the T2 interface, the NNE of the high value area of fractal dimension and topological value spreads out in the direction, which is high in the east and low in the west. On T1 interface, the NE of the high value area of fractal dimension and topological value spreads out in the direction, which is high in the east and low in the west. The fractal dimension and topological value are higher along the existing faults, especially in the intersection area of multi-directional faults and strike-slip fault overlapping area. The reservoir is mainly developed in the parts with complex fault development with high fractal dimension and high topological value.Conclusions:The fractal characteristics and topological structure of fault network system are affected by preexisting faults, regional stresses and strike-slip faults. Reservoir development is influenced by the fractal characteristics and topological structure of fault network system. The regions with high topological values are connected with faults of different order, which improves the connectivity of the fault network system. A large number of secondary faults are developed in the high fractal dimension region, which is conducive to the formation of traps.