The influence of such geological structures as dip slopes and back slopes on slope collapse patterns during earthquakes was examined by a DEM simulation. In the Mid-Niigata Prefecture Earthquake of 2004, a large-scale collapse and a surface collapse were reported in the region of strong motions. Since it is thought that the difference in slope collapse patterns is greatly influenced by the geological structures, the multi-layered ground was modeled by the DEM. As a result, it was confirmed in the DEM simulation that a dip slope can easily cause a large-scale collapse and a back slope can cause a small-scale collapse.