Abstract: The relationship of greenhouse gases emissions and vegetation types in wetlands is becoming a hotspot with global climate changes. The present study aims to characterize the emissions of greenhouse gases in sediments with different vegetations community in typical coastal wetlands. Sediment samples were collected from three vegetation communities of Phragmites australis, Spartina alterniflora, the intergrowth area of the two species and mudflat(no vegetation)in Chongming Dongtan wetland. The samples were incubated for 60 days and measured the releases of CO₂ and N₂O. The results showed that the total emissions of CO₂ in sediments under vegetations community(1 066-1 105 mg/kg)were much higher than those in mudflat((846±22)mg/kg)(P<0.05). No significant difference was found among 3 vegetation communities. Combined with the significant positive correlation between the total emissions of CO₂ and ω(TN)in sediments(P<0.05), the fact that can be deduced that ω(TN)in sediments rather than under the vegetation types community acts as a key role in control of CO₂ emissions from sediments. In contrast, the total emissions of N₂O in sediments with Ph. australis((0.41±0.01)mg/kg)were substantially higher than that under S. alterniflora ((0.23±0.01)mg/kg), the intergrowth area of the two species((0.32±0.01)mg/kg)and mudflat((0.21±0)mg/kg), respectively. This suggested that Ph. australis possibly facilitates the production and emissions of N₂O in sediment in the wetland. It is worth further studying on the roles of Ph. australis for the control and evaluation of N₂O emissions in a coastal wetland.