The southeast Tibet terrain with deep valleys and steep mountains is abundant in geological disasters such as landslides. This paper analyzes the landslide development regularity, discusses the relation between landslides and terrain, lithologies, structures, and rainfalls. The landslides occur during the rainy seasons May to September, most in June. The landslides trend to occur in sandstone, shale, mudstone, and active faults areas, but not in the granite and gneiss areas. Slope with over 30 degrees is also favorable for landslides.