The starting point of Motuo highway is Zhamu Bridge in Zhamu Town of Bomi County, and the end point of it is Lianhua Square of Motuo County. The whole length of highway is 117.3km. After Galongla Tunnel has been completed, a series of landslides along the highway can not be ignored. According to the field observation in 2006, 2007 and 2008, there were 66 landslides and rockfalls. In this paper, the K85 landslidebetween K85+500 and K85+580 in the highway is studied. This landslide is a small debris landslide of middle traction. The material, shape, deformation and environment are analyzed, the stability is calculated, and prevention measures are proposed.