Yancheng coastline sits at the intersection of the northern subtropical and warm temperate climates, which gives its coastal wetland ecosystem a unique character. Progressing from the land towards the sea, there are five distinct ecosystems: supratidal, upper intertidal, middle intertidal, lower intertidal, and subtidal. Each of these ecosystems showcases its own set of plant species.

The flora of Yancheng wetlands is diverse, encompassing 5 major vegetation groupings, which further break down into  11 types and 73 sub-groups. In total, there are 697 species of vascular plants from 121 families. The area also boasts a rich algal population with 96 freshwater algae species across 7 families, 211 offshore planktonic algae species in another 7 families, and 61 species of offshore macroalgae spanning 7 families.