Abstract: Phragmites australis is an important model plant in wetland reconstruction. We selected five representative Ph.australis swamps of reed that were reconstructed after sediment dredging, and a swamp that had not been dredged in Qinhu National Wetland Park as a control, and we compared the response of Ph.australis to the sediment dredging through measuring and analyzing photosynthetic physiological parameters during growing season and phenotypic parameters during the mature stage of Ph.australis. The results showed that the content of TN and TP in the sediment in Qinhu National Wetland Park had a significant decrease through dredging, specifically, the level of TN dropped to 480—1 080 mg/kg, and the level of TP to 536—585 mg/kg. The maximal net photosynthetic rate, apparent light use efficiency and apparent CO2 use efficiency had significant correlation with TN content in sediment in the swamps that were constructed after sediment dredging. In addition, the effective range of light use(the difference of LSP and LCP) increased significantly with increment in sediment nitrogen content. However, TP in sediment had significant correlation with only apparent light use efficiency. The length, area, dry weight of the 3rd leaf and the aboveground biomass had significant positive correlation with TN content in sediment, but no correlation with TP content in sediment. Extensive dredging in some sample plots may have negative impact on the growth of Ph.australis. Therefore when sediment dredging and reconstruction of aquatic vegetation need to be done, one should consider the impacts on aquatic plants with different adaptation to sediment (nutritional conditions). Dredging recklessly in large scale may create new limit factors in the reconstruction of aquatic vegetation.