Becaouse the landslide and debris flow are characterized by strong suddenness, short duration, quick disaster-causing and heavy damage, they would destroy various structures, such as houses, bridges, etc., damage farm land, hydraulic engineering facilities, and road engineerings, and thus, result in enormous property losses and injuries & deaths of the people-life, and influence regional sustainable development. So, on the basis of the systematic theory and DPSIR model, the paper takes whole process analysis as a primary thought, and according to the typical characteristics of the landslide and debris flow, analyses its defense system. By synthetic analysis of pressent achievements about this problem, an integrated defense system on the landslide and debris flow is brought forward.