Based on the theory of natural disaster system, this paper analyzed the July 15, 2006 catastrophe in Xiangjiang River Basin of Hunan Province from the aspects of rainfall, flood, disaster effects and the disaster mitigation mode by using the field investigation results and the timely weather, hydrology observation data. And the resuits are as follows: the main hazards in rural area were flood, water-logging, landslide and debris flow, whereas water-logging in cities; the catastrophe was caused by the natural factors including the heavy rain du...