Abstract：The susceptibilities of debris flow to different rocks vary obviously；and the Xiaojiang River basin is taken as a case study to analyze the susceptibilities of debris flow to different rocks. Nineteen samples of weathering products of 9 kinds of rocks with different elevations and five samples of debris flow depositions are collected in five debris flow valleys in upper，middle and lower reaches of the Xiaojiang River basin. The hydrological characteristics of each sample are analyzed by liquid and plastic limits and permeation experiments. Three indices of hydrological characteristics，such as plastic limit wP，plastic index IP and permeability coefficient KT，are selected；and the Euclidean distance is employed to analyze the susceptibilities of debris flow to different rocks based on the hydrological characteristic analysis of the samples. According to the analytical results，the order of the susceptibilities of debris flow to these nine kinds of rocks in increasing sequence is as follows：basalt，argillaceous limestone，dolomite，slate，Quaternary deposit，sandstone，siltstone，phyllite and mudstone. In order to check this order，the susceptibilities of debris flow to rocks of various valleys in Xiaojiang River basin are calculated based on the results of susceptibility analysis. According to the susceptibilities of all valleys and distributions of debris flow valleys in Xiaojiang River basin，the susceptibilities of debris flow to different rocks are reasonable；and it may be helpful for the assessment of debris flow hazards and prediction of debris flow.
