Abstract: Relong Basin (RLB) is a fault basin, part of the southern Yadong-Gulu rift system, controlled by the Ningjinkangsha west piedmont fault (NWPF). Field mapping, remote sensing and digital elevation model analyses revealed three stages of alluvial fans distributing in the RLB. The first stage is that the fan formed at middle mid-Pleistocene, the second formed at early later Pleistocene, and the third formed at later later-Pleistocene. The three stages are corresponding to the interglacial and great precipitation epoch in the interstadial. In later Quaternary, in the interglacial and interstadial, with temperature rising, precipitation adding and runoff increasing, old fans were eroded and the new fans started forming. The rock uplift continues in later Quaternary in the area of RLB. Owing to the activity of NWPF, the RLB tilts from north to south and the denudation decreased from north to south since mid-Pleistocene.

Key words: Tibet, Basin, Uplift, Erosion, Climate