Debris flow and landslide are two types of common disasters in the mountain area of Beijing city, and among which debris flow is especially serious. There are 700 debris flow gullies distributed over 61 villages and towns of districts and counties of Fangshan, Mentougou, Changping, Huairou, Yanqing, Miyun and Pinggu. The heavy incidents of personal injuries and deaths, and properties losses from debris flow and landslide have occurred many times there. The action is of great significance for improving environment and protecting the source of water supply of Beijing city.