With the refined 3D ground coordinates, two ways of detecting the collapsed buildings were proposed using pre- and post-seismic HRSI stereo pairs. The first was to detect an individual collapsed building by comparing the height differences of corner points of buildings calculated from the pre- and post-seismic IKONOS stereo pairs, and the second was to detect the region of collapsed buildings by calculating the difference between the pre- and post-seismic DEMs generated again from the pre- and post-seismic stereo images. In addition, the pre-seismic DEM based on a pre-seismic topographical map was generated for detection comparison in the study.