Abstract: Based on remote sensing data and field investigation results, we divide the western margin fault of Gulu basin into six segments, including Nian Bo-Ding Moduo, Ding Moduo-Ba Renduo, Ba Renduo-De Mulai, West of De Mulai-Guo Longpama, Guo Longpama-Yan Ta, Yan Ta-North of Xiong Oucuo. From the geological and geomorphological phenomena, we conclude that the fault moves not only in the vertical direction but also in the horizontal direction. Furthermore, the displacement displays that the movement of the fault has actived several times in the two directions.

Key words: Gulu basin, Tibet, Late Quarternary, Fault activity