Abstract: Based on systematic analysis of historical data, the study of the effects of human disturbance including the cutoff projects in the Jingjiang reach and of the impoundment of Gezhouba Reservoir and Three Georges Reservoir on the channel degradation process between Yichang and Shashi in the middle Yangtze River is carried out. The discussion is focused on the relation between channel erosion volume and lower level change. It is found that the water level lowering process is mainly controlled by erosion volume in the early stage of historical channel degradation, but in recent period lower level depends much on certain pivotal reach segments with special geological and morphological features, such as the Lujiahe Reach. The effect of channel erosion on water level is becoming less obvious in the upstream of Lujiahe Reach, but the surface slope between Lujiahe and Shashi is increasing gradually. This indicates that the water level controlling function of the special channel morphology of this reach is becoming greater.