In view of the study on environment of Dianshan Lake Basin,the distribution of point. non-point sources and total input of pollutants into the lake were investigated completely. The dynamic changes of the pollutants in the lake were analysed. The fuzzy matrix was used for comprehensive assessment to water quality. The trends of water eutrophication were predicated with the phosphorous model. The countermeasures of water pollution control in Dianshan Lake were suggested.