A study on seasonal dynamic of waterbird was conducted at Ruoergai marshes from March to December of 2010 to establish baseline information for avian influenza surveillance and wetland conservation and management. A total of 26 050 individuals of bird, belonging to 48 species, 12 families and 6 orders, were recorded. Of 21 408 were geese and ducks taking 82.2% of all the birds counted. Two peaks of bird abundance occurred in waterbird spring (March) and fall (October) migration period and most less waterbird recorded in November due to summer birds left and wintering birds had not come. Gahai was one of the important wetlands in Ruoergai marshes and held the most numerous water bird species and individuals. Satellite tracking on Bar-headed geese Anser indicus breeding at Qinghai Lake in western China indicated that the Ruoergai marshes was an important stopover site for the Bar-headed geese Anser indicus breeding at Qinghai Lake in western China on their migration way. There, they would met with waterbird wintering in Yunnan and Guizhou province. Therefore, it is important to monitor the avian influenza in the Ruoergai marshes.