The nocturnal behavior of the 8 species waterfowls were observed from the middle of November 2006 to the middle of February 2007 at the artificial wetlands behind the seawall in Chongming Dongtan.The results showed that the waterfowls which forage or roost in the pond during the day,such as Spot-billed Duck (Anas poecilorhyncha),Mallard (A.platyrhynchos),Herring Gull (Larus argentatus) and Little Egret (Egretta garzetta),flied out of the pond during sunset and foraged or roosted in the farmland and forest area behind seawall and or intertidal mudflat at night,then flied in during sunrise.There was a strong significant difference between waterfowls which stayed in the fishing pond during the nocturnal period in their activities.Black-crowned Night-Heron(Nycticorax nycticorax)rested in the forest during the day and flied into the pond after 17:00-17:30,inhabiting bared mudflat and reed strip in the pond dispersedly,however foraging behavior actively observed after about 23:30 when the frequency of forage occurred over 70% of total nocturnal behavior.Moorhen (Gallinula chloropus) and Coot (Fulica atra) presented frequent activities at night on reed strip and water area around it.Their foraging behavior reached to the peak of 60%-90% during 21:30-2:30 and resting became the main behavior after 2:30-3:30. Little Grebe(Tachybaptus ruficollis)with frequently diurnal activities stayed in the pond at night and rested in the area with deep water.The results suggested that the nocturnal behavior of waterfowl was likely related with the mode of their diurnal activities.