Abstract: The Jialin River basin has a catchment area of 158,000 km², long-term average of annual runoff is 65.1 billoin m³,and it is the largest tributary of the upper reaches of theYangtze River.Owing to the stratum broke, and the rock weatherirg has been strong, and so the soil erosion has been severe in this watershed. In addition, there are population explosion and destroying deforestation. Such expansion, in return, aggravates the losses of soil and water flow the catchment area, thus forming a vicious circle. Though irrigation projects for controlling the floods and to silt up sediment,by tens of thousands, have been completed throughout the watershed, but long-term average of the erosion modulus achieved to 1100 T/km. So the Jialin river has become the highest sediment concentration tributary of the Yangtze River system. It is near to Futuo River which is a tributary of the Yellow River system, with the greatest sediment discharge among the rivers in the world. The average of annual runoff of the Jialin River is only 10% of that of the Yongtze River,but the average of annual sediment about 1.92×10⁸T is 45% of that of the Yangtze River, so far as the sediment concentration is concerned,it ranks the sixth among the major rivers in the world. sediment concentration among the major rivers in the world.Arguing from the river system point of view, this paper analyses the causality between the ecological equivalence of the watershed and the hydrologic properties of the river with the sedimentary source and its regional composition of the Jialin River. According to some typical reaches cases of fluvial processes of the Jialin River, this paper discusses the actions and effects of the flow with hyperconcentration of sediment for the geomorphologic process in this river.