Because of the ever-increasing global warming，the frequency of extreme rainfall and regional group slope failure events following the heavy rains in mountainous vegetated areas are getting higher and higher. An in-depth research of this problem is not only of great practical significance to landslide susceptibility assessment, but also of an extensive multidisciplinary theoretical value. The existing research achievements in relative fields mainly focused on the interrelation between rainfall events and landslide events, which are no genetic correlation, as well as the aspect of water-rock interaction in slope rockmass and soilmass。But the basic link of rainfall-landslide process chain — the transformation of rainfall into groundwater has received much less attention whether in permeable medium or in the penetration process. The response of groundwater in natural slopes to heavy rainfall is a complicated hydrologic-hydrogeologic process, which involves plants, animals and their life activities. The existing research accumulation in relevant fields provides realistic basis and certain theory reserves for investigating this problem, but it can not cover the kernel mechanism of the process yet. Probing "The response of the groundwater in vegetated slopes in mountainous catchments to heavy rain events" could provide  slope hazard warning and prediction with a more clearly  theoretical support, and it is also important for deepening the theory of landslides caused by groundwater.