Abstract: In this short note we briefly review the research of tectonic geomorphology and report preliminary results on tectonic geomorphology of the Keriya river, northwestern margin of the Tibet Plateau. A river is a fundamental element of geomorphology, which forms during evolution of geomorphology. And the Tibetan plateau is the giant tectonic geomorphology in the world resulted from continental collision. A river of the Tibetan plateau documents changes of its drainage, geomorphology, tectonics and climate. Therefore it can tell the evolution of the Tibetan plateau. Up to now we know little about history of a river in the world. The key issue is the age of a geomorphic marker. We make this issue clear by the Ar-Ar dating of the basalt on the top of the Xiyu conglomerate, which gave a mean weighted age at 1.1±0.1Ma. The Keriya Rive evolved since then. That is, the history of the Keriya River observed is younger than 1.1 Ma. The history of the Pre-Keriya River drainage that we can infer to the Maximum is not older than the Atushi age in Pliocene. During the Wuqia age in Miocene, no influence from the present Tibetan plateau can be found on the Wuqia sediments, which demonstrate that the steep margin and its plateau occurred postdating Miocene and its drainage, geomorphology, tectonics and climate have developed since then.