Based on the model study, the siltation of dredged channel under the condition of clear water and sediment-water mixture in Lianyun Harbor, Jiangsu Province and the experimental method under complex hydrodynamic elements such as tides, winds, waves and tidal currents are studied. The regularities of the variation of the velocity in the dredged channel in clear water are discussed as well. A group of curves such as water depth, velocity and angle has been plotted as a guide to the selection of a proper direction for a dredged channel. The intensity of siltation and the rate of deposition in the condition of sediment-water mixture, and the relationship between the dimensions of the dredged channel and the deposition amount can be estimated. Based on the model study, the siltation of dredged channel under the condition of clear water and sediment-water mixture in Lianyun Harbor, Jiangsu Province and the experimental method under complex hydrodynamic elements such as tides, winds, waves and tidal currents are studied. regularities of the variation of the velocity in the dredged channel in clear water are discussed as well. A group of curves such as water depth, velocity and angle has been plotted as a guide to the selection of a proper direction for a dredged channel. intensity of siltation and the rate of deposition in the condition of sediment-water mixture, and the relationship between the dimensions of the dredged channel and the deposition amount can estimated.