Abstract: Lianfeng and Zhaotong fault zones are located on the border region of eastern Sichuan-Yunnan Province, and it’s hard to carry out geological and geomorphologic survey for fault activities in this area because of the limitation of poor traffic and complex topography. Therefore, Quaternary activities of those NE-trending faults in this region are poorly studied. In order to acquire more knowledge about the Quaternary activity especially the Late Quaternary activity of these fault zones, we interpreted four level broad valley surfaces of the Niulan River cross the Lianfeng and Zhaotong fault zones based on the Google Earth 3D terrain data, high definition images of GF-1 and GF-2, field investigation and UAV aerial images. Then, based on GIS, we used the ASTER- 30 m DEM to get the longitudinal profile of the broad valley surfaces of Niulan River. Finally, combined with previous research on the geomorphic surface age and the deformation of the broad valley surfaces of Niulan River, we drawn several conclusions as follows: since Quaternary, Lianfeng and Zhaotong fault zones are a group of thrusting zones, of which Zhaotong-Ludian fault has the strongest activity, Lianfeng fault is the second, the activity of Huize-Yiliang fault is the weakest.

Key words: Lianfeng and Ludian fault zones, Deformation of the broad valley surface, Late Quaternary activity of fault