Abstract: Mode of fault occurrence, mechanical property of fault, cross-section curvature of fault, cross-section pressure of fault, the angle between maximum principal stress direction and fault strike, and lithology along the fault are selected to establish analysis model of sealing capacity of faults. Semi-quantitative assessment of sealing capacity of nine faults associated with four local structures is obtained according to different plane location and different depth. Result shows that sealing capacity of W10-1 and W10-3 is the best, W9 is the median, and W10-2 is the worst.