Daguangbao (DGB) landslide has a volume of 11.59 × 108 m3, which is the largest landslide triggered by 2008 Wenchuan earthquake. Its geological features are described in this paper. DGB region located in the middle of LMS fault belt is dominated by thrust faulting which resulted in regional thrusts and local imbricate structures. Site observation indicates that a bedding fault whose thickness is 3 meters is seated 400 meters below the landslide’s surface on south of the mountain. In addition, three sets of dominant joints controlled by regional stress, two high gradient faults on the north and west of the mountain and the eastern steep slope incised by the river create a potential failure boundary. We summarized the geologic precondition for the earthquake-induced DGB landslide.