Lingdingyang Bay is an important estuary bay in South China with important shipping functions，and there are important ports such as Nansha Port of Guangzhou Port，Western harbors of Shenzhen Port and Zhongshan Port on its east and west shores，and Lingding Channel and Tonggu Channel are important sea accesses for Guangzhou Port and Shenzhen Port. The major problem of harbors and channels in Lingdingyang Bay is sediment siltation. Based on the analysis of insitu data，remote sensing analysis，flume test，and measurement and analysis of silt density，we carry out a comprehensive analysis and study on sediment problems of harbors and channels in Lingdingyang Bay，including dynamic condition features for sediment movement，sediment sources and transport forms，characteristics of suspended load and bedload，sediment siltation features and mechanism of harbors and channels，hydraulic characteristic test of sediment，and fluid mud and nautical depth utilization. Maintenance countermeasures of harbors and channels are proposed based on the siltation characteristics of Lingdingyang Bay.