Abstract:After the "5·12" Wenchuan Earthquake,plenty of loose soil materials accumulated in Jianping Basin of Longxi River,which is the main source material for debris flows initiation.Three large-scale debris flows occurred in Jianping Gully in 2009 and 2010.In contrast with the pro-earthquake conditions,the terrain and rainfall have not changed a lot and are appropriate for the initiation of debris flow,so loose materials can be regarded as the most significant impact factor for the debris flow characteristics and its development trend.The results based on the analysis of loose materials and its consolidation impact shows that debris flows in Jianping Gully will occur frequently in 5 years.The possibility of catastrophic debris flow will be high.In the next 5~10 years,the frequency and scale of debris flows in Jianping Gully will decline if there is no significant change for the rainfall and no strong earthquake,while large-scale debris flows can also occur under extremely rainfall with low frequency.