Drainage evolution and reconstruction is an important method toretrieve regional tectonic history and paleoenvironmental changes. As one of the seven major river systems in China, the research on the evolution of Songhua River is limited, especially the question if there was a reversal of flow direction in the middle and upper reaches of the Songhua River in Quaternary has not been accurately addressed. Sediment is the direct product of river geological process and a key to the study of river system evolution. Therefore, the magnetic susceptibility, palaeomagnetism and elemental geochemical composition of Harbin Huangshan drilling core (HS) were analyzed in this study. The results show that the lithology, magnetic susceptibility and elemental geochemical composition of the sediments change significantly at the core 62. 3 m (0. 94 Ma B. P. ). The lithology of the core sediments changed significantly around 62. 3 m, which was the turning point of the two sedimentary cycles of river deposition. The magnetic susceptibility of the strata below 62. 3 m is very low, basically 0, with a very low variation range, while the element geochemical composition fluctuates sharply, showing similar geochemical composition to that of the lower reaches of Harbin section of Songhua River (Chalin, Mayan and Mudanjiang rivers). However, the magnetic susceptibility of the strata above 62. 3 m suddenly increases (99. 673×10-8m3kg-1) and presents a period high. With low variation, the element composition shows stable and small variation, and shows similar geochemical composition with the Jilin section of the Lalin, the Nenjiang and the Songhua rivers. The change in sediment source at 0. 94 Ma B. P. indicated that the flow direction of the river changed significantly, and the flow direction of the middle and upper reaches of the Songhua river reversed at this time. The geochemical record of water system inversion is also supported by river terrace geomorphology and sedimentological evidence (gravel size and alignment direction). In the Early- Middle Pleistocene, the upper and middle reaches of the Songhua River (Zhaoyuan- Yilan reach) flowed from east to west into the Songnen Lake Basin, and the lower reaches of the Songhua River flowed eastward through the Sanjiang Plain. In the late Pleistocene, the Jia- Yi watershed continued to rise under the influence of tectonic- geomorphological- climatic coupling, while the one side of the Sanjiang Plain continued to sink and the rivers on both sides of the Jia- Yi watershed began to retreat. Source erosion eventually led to the Jia- Yi watershed being cut through at 0. 94 Ma B. P. , the upper and middle reaches of the Songhua River being attacked by the lower reaches of the river system, and a reversal of the flow direction of the river. The river flowed from west to east through the Yijia Gorge into the Sanjiang Plain, and the modern Songhua River system was gradually established. This study will help deepen our understanding of water system evolution in the Songnen plain and provide research confirmation for exploring the consistency and regional difference of water system evolution in East Asia. At the same time, it is of great practical significance to investigate the background of natural resources in the Songhua River basin and even to develop and utilize the territorial space.