Abstract: Highly Incised Slope(HIS) is a new type of geological hazard in the mountainous region of Three Gorges Reservoir.Investigation and experimental analyses are carried out at 47 HISs in Wanzhou area.The findings show that there are four failure modes in HIS.They are collapse,surface weathering,diversity of weathering,and soil sliding or collapse.Factors of influencing on failure modes in HIS are(1) the HIS materials,HIS characteristics,the hydrologic and weather condition,the HIS shape,and the engineering treatment time.According to the different failure modes in HISs,stabilization methods are recommended to be the guideline of design and construction.