Abstract: The assessment of fault sealing ability of the Shigang fault zone in the Jinhu depression, northern Jiangsu is based on the faulting intensity, the orientation of the present-day crustal stress, fault sealing effects and fuzzy comprehensive judgment technique. There are greater differences in the fault sealing ability in different parts of the Shigang fault zone:generally open in the southern part and close in the northern part, which may be valid for the sealing of oil and gas. In the northern part, the secondary induced faults have better sealing ability, and may be considered as the barriers of oil and gas. Moreover, there are also differences in the fault sealing ability in different periods. The fault sealing ability in the Funing Formation is generally better than that in the Dainan Formation, especially best in the fourth member composed of mudstones of the Funing Formation, and better in the second member of the Funing Formation and the first member of the Dainan Formation.