Abstract: Based on the National Surface Water Environmental Quality Monitoring Network, the monitoring data of 1 178 comparable sections in the Yangtze River Economic Belt (YREB) during the 13th Five-Year Plan period were derived and sorted. Combined with the data of population, social economic and pollutant discharges, the correlations between the variation of water quality and various socio-economic development indicators in YREB were analyzed. The results showed that during the 13th Five-Year Plan period, the surface water quality of YREB had improved steadily, and the water quality was good. The water sections meeting Grade Ⅰ-Ⅲ of Environmental Quality Standards for Surface Water (GB 3838-2002) had increased from 76.2% to 86.5%, while the sections that were inferior to Grade V standard had decreased from 3.7% to 0.4%. The concentrations of total phosphorus (TP), chemical oxygen demand (COD) and ammonia nitrogen (NH₃-N), which were the main over-standard indexes of surface water quality in YREB, decreased by 32.4%, 10.9% and 53.3%, respectively. The concentrations of TP, COD and NH₃-N in the downstream provinces (municipalities) such as Anhui, Jiangsu and Shanghai were relatively high, and the concentrations of TP, COD and NH₃-N in some individual sections increased. The biggest driving factors leading to the change of waste/sewage discharge were the population, the proportion of secondary industry, and the discharge of main pollutants. During the 13th Five-Year Plan period, the state further strengthened the water environment treatment of YREB. The operation cost for waste water treatment facilities increased year by year, up by 30.2%. The water environment treatment in YREB achieved remarkable results. However, the pressure from socio-economic development and pollution discharge still existed. To ensure the continuous improvement on the water environment in YREB, further improvements on the quality and efficiency were needed.