Abstract: To understand characteristics of slope deformation of an open pit is very important for its stability evaluation, mining and slope deformation monitoring. However, it is difficult to predict due to the complicated mining conditions. In this paper, FLAC method is used to spatiotemporally analyze the characteristics of deformation of a stable slope and an unstable slope of an open pit, and the effects of excavated zones and multi-stage cutting on the slope deformation. The result indicates that FLAC is an effective method for analyzing the deformation of a slope either stable or unstble, and that excavated zones and mining velocity have some effects on the deformation.