The change of stage-discharge relation along the Jingjiang river is analyzed based on the field data before and after the impoundment of Three Gorges Reservoir. Results show that the water level during low flowrate at Zhicheng station decreased slightly. Apart from that, the water level during medium and low flowrate decreased to some extent at stations in the upper Jingjiang reach, among which Shashi station witnessed the largest decline of low water level. The water level in lower Jingjiang reach also decreased slightly under the same flowrate. Moreover, the change of stage-discharge relation in Jingjiang reach is mainly caused by the Jingjiang river erosion, in particular, the erosion in the low water river channel. In addition, the changes of low water level at Zhicheng station is caused by the sand hole and stone pond formed by the shallows of the Lujia River.