Since the Wuxi water crisis in Lake Taihu in 2007, the prevention and control of water pollution in Taihu Basin has drawn attention from the government. In recent years, Zhejiang Province has continued to take measures, i.e. classifying different sources of pollution, treating accurately sewage waste water, to improve the overall water environment quality. Based on the hydrological survey data of Lake Taihu in Zhejiang Province from 2007 to 2019 and the water quality monitoring results of the main inflow and outflow rivers of Lake Taihu, this paper comprehensively analyzes the temporal and spatial variation trend of water quantity, water quality and pollutant flux in and out of Lake Taihu. The results show that the average annual inflow and outflow of Lake Taihu in Zhejiang Province are 2.739 billion m³ and 2.642 billion m³, respectively. During 2007-2014, the net flow from the rivers are positive from 2007 to 2014, and negative from 2015 to 2019. The main reason for the increase of inflow from 2015 to 2019 is due to the influence of abundant precipitation. From 2007 to 2019, the concentrations of COD_Mn, NH₃-N and TP in the rivers around the lake in Zhejiang Province showed a significant downward trend, while the concentration of TN decreased. Except TN was still in the class V-inferior to class V water, the other indicators were in the class Ⅱ-Ⅲ according to the national water quality standard. At present, the COD_Mn and NH₃-N concentrations of the rivers around the lake have reached the target proposed in the overall plan for comprehensive water environment management of Taihu Basin (revised in 2013), while some water quality indexes of the rivers around the lake remains to be ameliorated, such as TN and TP concentrations. The annual average influxes of COD_Mn, NH₃-N, TP and TN are 11200, 1800, 300 and 9000 t, respectively, and the outfluxes of them are 11300, 1000, 300 and 6200 t, respectively. The net fluxes of COD_Mn are positive (outflow>inflow), while the other indexes show negative (inflow>outflow) in most years. The water quantity is the key factor affecting the flux into the lake.