Abstract: Based on the landslide deep displacement monitoring data, we analyzed the depth of landslide sliding zone at the 3rd High School Landslide in Badong County, Hubei, and according to the geological catalog in pile-holes, we compared the monitoring data with the observational landslide structure, sliding direction and sliding zone depth. The results showed that the reliability of inclinometer data near the earth surface was weakened due to the influence of external factors, but the sliding soil identified by monitored data was consistent with the results of observed pile-hole. The research indicated that landslide deformation monitoring by borehole inclinometer is an important method for landslide controlling design.