AbstractA proper model was selected in this paper for analyzing the capacities of water environment of Poyang Lake for accommodating the several main pollutants quantitatively on the basis of the existing data. The results show that the maximum annual capacities of COD, TP and TN are 768288.5t, 7161.2t and 143224t respectively by taking the second-class national water standard as reference and they are 1576982.5t, 14322.4t and 286448t respectively by taking the third-class national water standard as reference. The paper further analyzed the system adjusting capacity of water environment of Poyang Lake with the following results: The flood adjusting amount for the five upper rivers of Poyang Lake at their maximum inflow reaches 74 to 246×108m3. The flood-adjustment rate is about 16 to 60 percent with its annual average adjustment rate of 34%. The occurrence of serious flooding disaster of Poyang Lake is 16%. The carrying capacity of the flooding-proof system of the lake region is relatively low. About 29.9 to 53×108 m3 water in the dry season are needed for maintaining ecological functions of the lake. Water and soil erosion, and land desertification in the lake region are not under control currently. Annual ecological and environmental cost reaches 19.85×108 RMB occupying 10.56 percent of the total GDP of the Poyang Lake region. In a word, the economic, social and environmental development coordinating level of the Poyang Lake region is low.