The subaqueous delta is a sink on the terrigenous clastic continental shelf. It contains tremendous information on environmental changes influenced by both the sediment supply and marine environmental dynamics. The results show that the sensitive populations of grain-size are distinctly characterized by periodicity and a definite trend. The characteristics of fine grained sensitive populations were mainly relative to the changes in sediment supply from the Yangtze River, and the periodic changes and the trend of the coarse sensitive population reflect either the influence of extreme events, such as storm, or changes in the main course of Yangtze River.