Abstract: Much attention has been paid to Lengmugou debris flows in Baoxing County after the Lushan earthquake. Affected by earthquakes superposition, the structure of the provenance is more wider and looser, and two large-scale debris flows are activated successively in August 18, 2010 and May 23, 2013 under the condition of triggering heavy rainfall. Combining with the provenance conditions, the paper makes the effects on the source provenance clear through the provenance response study under the action of earthquake, as well as the change characteristics of the source volume. Meanwhile, the paper also concludes inductively the causes of the provenance reserves increase through comparative analysis, and different types of source related transformation relationship between each other. Firstly, the Wenchuan earthquake is indirect contribution within the provenance in the watershed, and the Lushan earthquake induced directly, the same is likely to be indirect contribution to the next earthquake. Secondly, the provenance response of indirect contribution from the slope debris flows has been translated into collapse-type source and channel-type source. The paper obtains the preliminary understanding to the quantity change of the provenance the earthquake stacks effected, with more hope that the results provide certain enlightenment function on monitoring and warning research in debris flow disaster.