Shan Yang County Shaanxi Province, China has suffered from heavy rainfall from July 23rd to 24th, in 2010. It triggered several landslides in the Xigou gully which located at the upstream of Qiao Ergou gully in Qiao Ergou village of Gaoba Town in Shan Yang County. 6 people were killed, 19 people missing and 3 people wounded. It was influenced by local climatic conditions, geological conditions and topography conditions, and its formation mechanism was unique. The paper revealed the formation mechanism of this landslide.