Abstract: The analysis of the exchange of the suspended and surface sediments in the Lianyungang harbor and adjacent sea area was carried out based on the grain-size spectral calculation method, which provides a theoretical basis for the general layout of the breakwater entrance in the Xuwei port and the siltation research on the navigation channels in the Lianyungang harbor. From the calculated results it is found that the sediment exchange ratio in the main Lianyungang navigation channels and Xuwei navigation channels 5 m outside the isobaths is between 0.1 and 0.2, and the siltation intensity is relatively low, which is beneficial to the channel maintenance. The exchange ratio in the navigation channel 5 m inside the isobaths is between 0.3 and 0.4, and the suspended sediment deposition adds a contribution to the channel siltation. It indicates that there is a greater sedimentation in the section of this navigation channel. And the calculated results are consistent with the distribution characteristics of the measured siltation intensity, being a scientific basis for further researches on the channel siltation and maintenance. The sediment exchange ratio of the sand spit in the Guanhe River estuary is below 0.2 under the normal climate conditions. The sediment exchange ratio in the surf zone 5 m inside the isobaths is more than 0.5, which indicates that the suspended and surface sediments exchange occurrs frequently. The particle size components of the sediment frequently exchanged are the fine particle size sediment ( < 62 μm). The analysis results show that it is necessary to construct a sediment barrier and its head should be placed outside the surf zone for reducing influences of siltation on the normal port operation. The above results provide a case study for applying the grain-size spectral calculation method to the harbor and waterway engineering.