Changes of chlorophyll and carotenoid content,SOD,MDA,proline content in leaves of 5 emerged plants(Iris pseudacorus,Pontederia cordata,Typha orientalis,Thalia dealbata and Spiked loosestrlfe) under sewage submerging were studied by potted plant experiments,and their effects of purifying sewage were discussed by analyzing 6 water quality parameters: TN,NH+4-N,(NO-3-N+NO-2-N),TP and COD.The results were as follows: the chlorophyll content of 5 emerged plants fluctuated at the initial submerging period,but declined towards the end of sewage submerging,the carotenoid content had the similar tendency.During 15th-30th day after submerging,the change of SOD activity of both I.pseudacorus and S.loosestrlfe was little,and that of other plants went down,but SOD activity of whole plants increased after 45 days of submerging,and MDA content had a trend of rising at the later submerging period even though the change was not very acute in 15-30 days of submerging.The proline content of I.pseudacorus and P.cordata varied greatly,and that of other plants were not evident.The results from the comparation of physiological responses of five emerged plants showed T.orientalis,which wasn't sensitive to sewage submerging,was an more enduring specie to sewage submerging.On the other hand,the removal rates of T.dealbata to TN was 61.75 %,that of T.orientalis to TP was 87.50 %,so they were fine water punfication plant.