Abstract: Darong landslide in Cengong county happened on June 29, 2012. It is a large-scale gentle inclined landslide accumulation deposits. The gradient of slope in the main accumulation area is between 8to 20.The dip angle of the interface between the bedrock and accumulation layer in main sliding area is between 4to 11.Strongly weathered layer distributes in the underlying bedrock. Since 2009, artificial soil has been continuously piled up on the catchment area on the left of accumulation area. Based on characteristics and 3D numerical simulation analysis, the artificial soil and heavy rainfall are the common inducing factor of Darong landslide. They firstly locally made the artificial soil area unstable. Its foot is therefore damaged, and gradually leads to the slope failure. The sliding surface is in the strongly weathered layer. In combination with other typical cases, the structure characteristics of the large gentle inclined accumulation landslide are summarized. Heavy rainfall is the necessary inducing factor of this landslide. When these landslides occur, the local underlying bedrock is often driven.