Abstract: Based on the historical bathymetry data of the south channel of the Yangtze River estuary, and the water depth of the fixed cross-sections four times every year from 1997 to 2011, the process of changes in the volumes of the overall and sub-regional south channel is analyzed in this study. The paper focuses on the characteristics analysis of the tide and changes in the volumes along 5 m deep river channel. The analysis results show that: (1) from 2001 to 2004, the Ruifeng shoal ditch and the human disorder sand-digging on the sand ridge of the south channel brought about a remarkable change in the river channel’s volumes while the deep channel of both Changxing waterway and the main channel of the south channel were in a deposition period; from 2001 to 2007, the south channel the alternate deposition and erosion in the flood season and non-flood season . After 2008, the south channel presented the alternate erosion and deposition in the flood season and non-flood season. This situation also occurred before 2001. However, this seasonal variation weakened after 2008. (2) There is a long-term increase in the riverbed volumes of the south channel. The deposition continued to exist in 2008 as the ebb tide was dominant, instead of the flood tide dominant, in the Ruifeng shoal ditch and Changxing waterway, starting from 2001. There was deposition in the north and erosion in the south at the upper section of the main channel of the south channel, and the south section of the middle-lower reach was scoured, with its thalweg moving to the north. But the erosion of Ruifeng shoal resulted in a trend of increasing in the south channel volumes. Since 2008, the river channel has been in a period of development. (3) There is a slight deposition along the deep channel and an erosion along the shoal, and there is a great amount of sediment, carried by flow from the ditches on the middle section, accumulating along the lower Ruifeng sand spit. The fact is found that the Ruifeng sand spit has been eroded severely since the operation of the Three Gorges project.