Abstract: The south passage is a 3rd grade branch of the Yangtze River mouth. It is one of the most important ship navigation channels of the city of Shanghai. There are tidal flats on both sides of the passage. Based on the hydrological data of 2002-2013, combined with the data of runoff and sediment discharge from upstream, and the concerned data of the South Passage, we made a comprehensive study of the evolution of the south channel. The results show that the upper part of the South Passage is continuously under scouring and remains under a state of instability, while the middle reach is characterized by erosion in channel and siltation on beach and basically remains is in a rather stable state. Under the influence of both the natural process and human activities, the Nanhui point bar is under the state of stable channel and moving beaches at present, whereas the Jiuduansha side remains unstable on beach and in channel. The shift of thalwag is small. The current status of the passage indicates that the South Passage remains good as a transporting channel.