Abstract: Many Meso-Cenozoic rift basins developed in eastern China, which is difficult to form the compressional structural style. This paper studies a strike-thrust fault in Chenbao oilfield of Subei Basin and analyzes its geometric characteristics and forming mechanism based on high quality 3-D seismic data. It is shown that the reflections of T₂³, T³₃, T₀⁴ were cutted by the strike-thrust fault, which strike to EW and incline to south with a high angle. The main activity periods of the strike-thrust fault were E1f era. The strike-thrust fault was formed by slide gravity and strike induction under its deep background. The source rocks, hydrocarbon migration and traps were strongly affected by the strike-thrust fault. The oil trap of Chen9 block has been evaluated as an important petroleum potential.