The response analysis of plant leaf traits and photosynthetic physiological characteristics to flooding is helpful to understand the leaf construction model and photosynthesis mechanism of marsh wetland plants in the flooded habitats. The sample area was divided into three levels based on the length of the still water retention time in the lake flooding area of Xiaosugan Lake wetland: I(mild flooded field, still water retention 60-90 d), II(moderately flooded area, still water retention 90-150 d), III(heavy flooded area, still water retention 150-210 d). The results showed that with the increasing still water retention time, the soil moisture was gradually increased, the soil salinity and photosynthetically active radiation were gradually reduced, the coverage and density of wetland communities were increased, the aboveground biomass exhibited increase first and decrease afterwards, the leaf area of Glaux maritima L increased and the leaf thickness, net photosynthetic rate, stomatal conductance decreased, the