According to the current situation of river regime and navigation-obstructing properties in the south passage,we analyze the development conditions of the south passage waterway,and discuss the basic idea and framework of further channel regulation.The study result reveals that the river regime of the south passage is relatively stable due to the Yangtze estuary deepwater channel improvement project and reclamation work of Nanhui eastern side flats,therefore it is in a good state of waterway exploiting.But the channel development may be restricted by Jiuduansha wetland national nature reserve zone and safe operation of nearby port and waterway.For the further development of the south passage waterway,we should focus on the estuary integrity,stand on the channel condition,and emphasize the construction opportunity.