The influence of laser beam divergence angle on the positioning accuracy of scanning airborne light detection and ranging (LIDAR) is analyzed and simulated.Based on the data process and positioning principle of airborne LIDAR,the errors from pulse broadening induced by laser beam divergence angle are modeled and qualitatively analyzed for different terrain surfaces.Simulated results of positioning errors and suggestions to reduce them are given for the flat surface,the downhill of slope surface,and the uphill surface.