The“trimodal distribution'' of the Changjiang Diluted Water (CDW) in June, 1980 is analyzed and some dynamical aspects of its path are discussed in this paper. The main results are as follows:(1) The “ trimodal distribution”of the CDW may be caused by the interaction of large discharge of Changjiang River, strong tidal currents and mean alongshelf currents (the “ East China Sea Coastal Current ” and the “ Tai wan Warm Current”) within the estuary and over the adjacent shelf and the complex inner shelf topography. (2) The large discharge, the rapid cross-shelf increase in depth and the relic river valley in studied area have a direct influence on the behaviour of the path of the CDW (3) A simple estimation shows that the mean alongshelf current，general1y speaking，may have a limited influence on the path of the CDW.