Abstract: Using RS (remote sensing), GIS (geographic information system) and field survey comprehensively, this study analyzed the coastline and wetland changes in Yancheng during 1987-2018. The results show that the impact of human activities on the coastal wetlands was significant. Due to human reclamation, the natural coastline had been reduced by 30.23% and the artificial coastline increased to 43.92%. The natural wetland in coastal areas are reduced by 106 751.6 hm². In addition, the reclamation areas are mainly located in the eroded shore and the transition shore between siltation and erosion. After reclamation, the silting and eroding regulation were changed in the whole shore. The siltation accelerated at the silting shore. The erosion accelerated in the transition shore between siltation and erosion. This led to the alternate point of siltation and erosion moved southward Port construction was another important human activity, which had a serious impact on coastline characteristics and wetland area. Sheyang Port is located in the transition shore between siltation and erosion and Dafeng Port is located in the eroded shore. The natural coastline was shortened, and the proportions of artificial coastline accounted for 25.45% and 47.53% in Sheyang Port and Dafeng Port respectively. After the construction of Sheyang Port, the rate of wetland loss was 18.4 hm²·a^-1, which was lower than before the construction. The wetland reduction rate of Dafeng Port was 335.3 hm²·a^-1, which was nearly 5 times of that before the construction of Dafeng Port. Due to the specific pattern of siltation promotion by port construction, the spatial pattern of siltation on both sides of the port had changed periodically. It had evolved from "double arch" to "arch/S-shape" and then to "arch/slope".