This study utilizes the unmanned aerial vehicle (UAV) to acquire high resolution images for feature matching, resulting in a point cloud. A progressive morphological filter is used to filter out nonground object points from point cloud. Multi-scale and different shape filter windows are adopted for the morphological filter to achieve good performance. The results show that multi-scale and multi-shape window can improve the performance of morphological filter compared with single direction filter window, as nonground objects cannot be completely removed with single direction filter window. With multi-shape or 2-D filter window, buildings can be effectively removed and ground points can be reserved.