Abstract: By analyzing the triaxial consolidation drained shear test data under low confining pressure derived from ten constructed and non-constructed projects, the corresponding peak strength and residual strength are achieved, and the normalized residual strength curve considering softening of rockfill is fitted. Based on the curve, the finite element dynamic stability calculation is implemented using the rigid sliding block method. The different conditions with or without softening of rockfill materials are taken into account respectively, and the calculated results are discussed. The results show that the rockfill material is easy to soften under low confining pressure. The normalized residual strength curve of rockfill can provide reference for the finite element dynamic stability calculation considering softening. The minimum safety factor of dam slope, the slippage of slip plane and the difference between considering softening or not gradually increase with the increae of the peak acceleration during the earthquake. It is important that the softening of rockfill of dam slope in the analysis of the ultimate aseismic capacity of high face rockfill dam should be considering.