Abstract: The comprehensive analysis of water quality and meteorological data in Changhu Lake for 2014-2017 demonstrates that the main problem of water quality in Changhu Lake is the eutrophication. The main pollution indicators are total phosphorus(TP), total nitrogen (TN), and chemical oxygen demand (COD) and biochemical oxygen demand (BOD₅) on five days. Variations in these indicators show significant spatial and temporal heterogeneity. In the space, the differences of TP, TN and COD between inlet and outlet in Changhu Lake was obvious, but there was no significant difference in BOD₅. In terms of time scale, the overall water quality was improved during the period from 2014 to 2017, but the indicators showed that seasonal variations appeared at different levels, and the water quality was significantly affected by meteorological factors. The TP was positively correlated to the rainfall, while TN was negatively correlated with the temperature.