Dafeng approach channel is a natural depth waterway which locates in Xiyang channel of the radial sand ridges area along north Jiangsu province.In order to provide a scientific basis for the construction of Dafeng 150 000 DWT approach channel,we carried out the trial excavation from 2012 to 2013.The dredging thickness is 3.1 m and the total siltation thickness is 1.72 m in 12.5 months.The back silting intensity during the stable period is 0.12 m per month and the influence of a normal year wind is limited.The research provides reference to Dafeng approach dredging and related waterway construction.