Abstract：The theory of load-unload response ratio(LURR) is introduced to analyze dynamic slope stability. The LURR model of slope is established by studying laws of load-unload response ratio of slope under seismic load；and a concept of load-unload response degree(LURD) is suggested to substitute the factor of safety. With this concept，a new method of dynamic slope stability is explored；and deformation analysis and stability evaluation are well combined. Taking the right bank of Majiayan reservoir for example，a dynamic analysis is performed using the suggested method. Compared the calculating results with pseudo-static method，finite element method and Newmark sliding block method，it is verified that the presented method is reasonable. The new method has priority to traditional dynamic analysis method in precision；and it can carry out deformation and stability analysis at the same time.
