Based on hydrographic and anchored-station data it is shown that a persistent NE-SW front exists inside Hangzhou Bay year-round. This front is actually the merging of the secondary Changjiang plume front and the Qiantang plume front from the upstream side of the bay. At neap tides during the low runoff periods these two plumes can readily be identified. Our findings suggest that suspended sediment is transported into the bay through the northern end by the secondary Changjiang plume. The front inside the bay acts to concentrate suspended sediment and transport it southwestward into the bay.