Abstract: Since the 18th CPC,ecological civilization construction has been advanced continuously, and remarkable achievements have been made in ecological environment protection and the construction of a beautiful China.Therefore, the effectiveness of lake governance and the improvement of water ecological environment in the middle and lower reaches of the Yangtze River have been widely concerned by the whole society.This study aims to elucidate the dynamics and change trend of lake area, water transparency, nitrogen and phosphorus concentrations, algal bloom and aquatic vegetation before and after the ecological civilization construction from 2010 to 2021 using satellite remote sensing inversion and long-term positioning observation.The annual maximum and minimum water surface areas of lakes have increased in the past 10 years, indicating that the encroachment and shrinkage of lakes have been eliminated and water environment capacity has markedly increased.Water transparency of the lakes has no marked trend around 0.75 m for multi-year average.Biochemical oxygen demand, total nitrogen and ammonia concentrations decreased significantly, but dissolved oxygen increased slightly.Chemical oxygen demand and total phosphorus concentration fluctuated without the marked decrease trend.Annual average total phosphorus concentration was 0.061 mg/L in 2020,which still exceeded the Class III water quality standard of 0.05 mg/L for lakes and reservoirs.All these results indicate that remarkable achievements have been made in water pollution control overall.Influenced by meteorological and hydrological conditions, the areas of cyanobacteria blooms in Taihu Lake and Chaohu Lake fluctuated greatly from year to year.Under the background of climate warming, the areas of cyanobacteria blooms have not increased, indicating that the prevention and control of cyanobacteria blooms has achieved very positive results.Unfortunately, the overall decline of aquatic vegetation was observed in lakes showing the degradation trend of macropyte-dominated ecosystems has not been significantly suppressed.Therefore, the improvement of lake water environment and the restoration of water ecology faced many difficulties and challenges.It is suggested that more studies on pollution control and reduction, the protection and restoration of lake ecosystems, and the impact of climate change on lake ecosystems should be strengthened in the middle and lower reaches of the Yangtze River.The purpose is to improve the level and effectiveness of lake protection and control, and effectively ensure the green and high-quality development of the Yangtze River Economic Belt.