Abstract: Objectives To described the quality of drinking water in Beijing through on-line monitoring data in 2014; to analyze the characteristics of water works,water supply networks and water quality in some districts of Beijing to provide reference data for formulate regulatory schemes of supervision department and to optimize the on-line monitoring system.Methods The data collected from seven monitoring points were sorted out and analyzed on data validity, monthly and daily averages, district differences and so on; and five indexes on pH value, turbidity, residual chlorine, conductivity and total organic carbon (TOC)were compared.Results According to the statistics analysis, the five indicators of the monitoring data are valid and the daily average values are statistically significant. Because of Fengtai district and Daxing district located in the south-north water switch point, the changing of the TOC is consistent with water switch time.Conclusions The quality of drinking water in Beijing municipal pipeline network could meet the requirements of the national standards. The stability of on-line monitoring system was good, which could reflect the water quality in the network to certain extent, and the iprovement of on-line monitoring is indispensable for comprehensive analysis and popularize among the water works in the capital.