The extension and uplift of the Tibetan Plateau has not only shaped the landforms of the plateau and surrounding areas, induced climate changes, but also greatly changed the drainage pattern around the plateau edges. River sediments are the most direct evidences in recording river evolutions. In this study, we focus on the drainage evolution of Jinta'nanshan Mountains, northeastern margin of the plateau. The main methods we used are lithology components and fabric statistics of fluvial gravels from an old gravel layer and modern rivers. In the field we found that a layer of rounded and well sorted fluvial gravels was preserved on the top surface of the Jinta'nanshan Mountains. The gravels are composed by different kinds of rocks, which are far more complicated than the local lithology. Results of gravel lithology statistics show that main components are litharenite, quartz sandstone and chert, which are not derived from local areas. In order to find their sources, we also counted lithology components of fluvial gravels in 7 major river of the northern Qilian Mountains. The results indicate the differences between the main components of the rivers are large. But the differences well coincide with the differences of the lithology components for gravels lying on the Jinta'nanshan Mountains. Correlations of the content and the spatial distribution for gravel lithology components on the surface of the Jinta'nanshan Mountains with that in the 7 rivers indicate that some parts of the gravels were derived from these rivers. Additionally, the gravel layer fabric showed that the ancient flows were northward in eastern part of the Jinta'nanshan Mountains, while the flows in western part are relatively complex. Based on the gravel lithology and fabric analysis, we speculate that Jinta'nanshan Mountains gravels were mainly derived from the rivers draining the Qilian Mountains. Combining the upper analysis, we can conclude that when the gravels were depositing on the surface of the Jinta'nanshan Mountain, rivers draining the Qilian Mountains were swinging or joining together around the Jinta'nanshan Mountains, which caused the paleo-flows have complex flow directions. During Mid-Pleistocene, uplifting of the Jinta'nanshan Mountain caused the Heihe River and Beida River incised the mountain and formed the Zhengyi Gorge and the Yuanyang Gorge, respectively. Since then, the two relatively independent and stable drainage systems were formed in this region.