The monitoring data is undoubtedly important to the water quality monitor- ing department. The proficiency testing is an important way to improve the monitor- ing capacity and enhance the quality management of laboratories. It plays an impor- tant role in ensuring the accuracy, integrity and comparability of monitoring data. In this paper, the positive role of proficiency testing in the water quality monitoring was analyzed. In addition, how to improve the water quality monitoring capacity and the quality management level of laboratories through the proficiency testing was also discussed.