Abstract: Numerous experimental data and post-earthquake investigations have shown that the seismic acceleration is significantly amplified along the height of the slope and leads to the generation of cracks at the crest of slopes. To explore the impacts of seismic amplification on the development of crest cracks and the slope stability. Based on the upper-bound theory of limit analysis and pseudo-static method, the seismic stability of crack slope which considering the amplification effect was established, and the influence of the seismic amplification effect on slope stability and the development of cracks was obtained. The results show that the safety factor of the crack slope decreases with an increase in the seismic amplification factor and the safety factor for both steep slopes and gentle slopes decreased by about 10% after considering the seismic amplification effect, and that as the seismic amplification factor increases, the crack gradually moves away from the slope crest, while the depth of the crack decreases. The amplification effect on the position and depth of the crack is significant when the seismic acceleration at the bottom of the slope is large. According to the upper bound solution of seismic crack slope safety factor c/γHtanφ and the slope parameters F/tanφ present the characteristics of power function, a safety factor calculation expression is obtained by fitting, which can be used to quickly evaluate the impact of seismic amplification effect on the safety factor of crack slope in practical engineering.