Lvsi approach channel is located in south margin of Subei radiation shoals. The approaching channels are all natural depth at radial sand ridges in North Jiangsu. In order to provide a scientific basis for the expansion of the Lvsi approach waterway, we carried out the trial dredged channel in Xiaomiaohong waterway. The siltation observation includes the topographic survey, hydrologic survey, bottom sampling, etc. The result indicates that the siltation of trial dredged channel is week in the normal condition, the influence of a normal year wind process on the siltation is limited, the significant sudden siltation does not happen after Typhoon Muifa with 5 to 10 year frequencies.