According to Weber's ideal hype of social actions and different actors motivation，social actions are divided into four types including.traditional action，emotional action，purpose rationality action and value rationality action. The paper quantitatively investigates residents' environment awareness including the change of wader qualify of Taihu Lake，pollution impact on local residents' production and living, and residents' participation in environmental projection and so on. Then，according to the investigation，it concretely analyzes residents' social actions in he process of pollution formation and governance. Residents' traditional action in daily life and the purpose rationality action in the pursuit of agricultu re“high yield” collectively and unconsciously cause the endogenous pollution in Taihu Lake. The residents' atitude changing from initial capering to layer resistance in the process of enterprises' development indicates the interweaving of residents'“earning money”purpose rationality action and “heath" purpose rationality action. Residents' performance indicates collective silence and passive obedience in the process of the governmental environmental management，showing residents' emotional actions' of being helpless and dependent on government.