Ms7.0 giant earthquake took placed in Lushan County, Ya’an City at 8:02,April 20,2013, and according to field investigation, the most of secondary mountain disasters were collapses with small and median scale volume.Five principal types of secondary mountain disasters consisting of conglomerate collapses,sandstone collapses,carbonate stone collapses,landslides and long run-out landslide-avalanche were proposed and the characteristics,mechanism and influence factors were analyzed.The regional geological environment and structure were regarded as the primary elements through preliminary analysis, and the large amount of loosen materials were easy for occurring debris flows and landslides triggering by the storm and continuous rainfall, which will seriously threat the reconstruction and lives in the rainy season for decades,therefore the post-earthquake effect as well as the monitoring and pre-warning strategy should be carried out in meizoseismal area and especially in reconstruction settlements.
