In view of the bank slope seepage failure in Jinjiang river reach,we analyze the reasons for the failure based on a practical case and find out the main influential factors for the failure,i.e.geologic factor,hydrologic factor and meteorological factor.The geological condition of Jingjiang reach includes single sandy soil structure,upper layer clay and lower layer sand,as well as interlayer and cross layer which consists of sand and clay.The supply relationship between groundwater and river water was complex.River water supplies groundwater in the flood season,and groundwater supplies river water in the dry season.After the impoundment of the Three Gorges reservoir,water level dropping speed was accelerated,and the seepage gradient between groundwater and river water was increased.The occurrence frequency of heavy precipitation weather is still high,and its range keeps still large.Finally,the bank slope seepage failure mechanism of Jingjiang beach is revealed