By contrastive analysis on evolution characteristic of river and water depth condition of Jianshan bend of Qiantang estuary former and after river-training and polder Engineering,the paper makes a analysis and discussion on port construction on shouthwestern bank of Jianshan bend of Qiantang estuary.

The obvious technical results and economic efficiency have been gained in construction of Jingtang Harbour Area,Tangshan Port due to adhering the road of studying the applicable technology for the practical engineering,using the new ideas of science and technology to guide port construction.

Based on the statistics of variation of scouring and siltation at multiple cross sections of Hangzhou Bay north shoal within a year, the regularities of scouring and siltation within a year together with the reasons are put forward Moreover, the trend of scouring and siltation of many years and port construction conditions of the shoal are analyzed

In this paper,the formation cause of the north coast of Hangzhou Bay is expounded from the historical changes in the coast,the statistics and analysis of tidal current action,geomorphological development,sediment migration and estuarine evolution trend in the area are made,and a preliminary analysis of the harbor construction conditions along the coast is also made.