In order to explore the effect of different ecological zones and their above plants in the organic matter cycling of the whole tidal salt marsh, indicators such as total organic carbon (TOC), total nitrogen (TN), C/N ratio, ?C and ?N of surface, core sediments, and plants of tidal salt marshes in North Jiangsu Province are analyzed. Subsequently, distribution regularities of these measurement indicators are discussed, and the biogeochemistry processes between sediments and plants are also analyzed. Lastly, the organic matter sources of different ecologic zones in tidal salt marsh are evaluated, and the organic matter accumulations in different ecologic zones induced by their plants are also compared. These results indicate that TOC, TN, C/N ratio and C showed obvious zonal distribution. The organic matter sources are dominated by marine input in the silt flat, flat, and the transition zone between silt and flat, and are controlled by terrigenous input in s flat. plays an important role in the accumulation of organic matter in the whole tidal salt marshes ecosystem. In the study area, the annually increased TOC, organic matter and TN in the , and reed flats reach 6,451, 12,043 and 536 t, respectively. The amount of TOC, organic matter and TN accumulated in the flat is more than that in other ecological zones, which shows that the flat exert a non-replaceable effect on the material cycle and exchange in the whole tidal salt marshes ecosystem.