Abstract: Maoping landslide, the largest ancient landslide in Geheyan reservoir area, with a volume of 23.5 million m3, is located on the left bank of Qingjang River at 66 km upstream of Geheyan dam. Since the reservoir impounding started in April 1993, the slide was reactivated and slowly deformed. A village with 290 inhabitants had to be relocated. Since then the landslide has been in persistent deformation and upto now a maximum displacement of 2100 mm was recorded. On the basis of investigation of the slides constituent structure and formation mechanism, the paper deals with an in-depth study of the deformation characteristics and induced mechanism of the ladnslide through comprehensive analysis of the observation data in 10 or more years and a prediction is made on its development tendency.