The major goal of this project was to check the whole processes that influenced the monitoring data quality obtained from the “The Environment Monitoring of the Water Quality in the Northern, Middle, and Southern Area of Taiwan” program. This year, the monitoring data quality had already been reviewed and the related reports were submitted to Environmental Protection Administration (EPA) each month. The implementations of management, evaluating and analysis of data quality of environmental water were also finished, including stipulating the quality goals of monitoring data, reviewing and audition of the Quality Assurance Project Plans (QAPPs) and Standard Operation Procedures (SOPs) for the proposal “The Environment Monitoring of the Water Quality in the Northern, Middle, and Southern Area of Taiwan”. Also attended the working conferences of the plan, executing checking in on site sampling work for 162 times / 460 monitoring stations and in laboratories for 80 times / 84 person-times, held blind tests for 4 times, assessed the technology of sampling staffs and set up the list of qualified personnel, set up the qualified tabulation for measuring instruments used in sampling field. In addition, we appointed a professional person to keep in touch with EPA for checking the water quality monitoring programs. In establishing environmental water quality monitoring annual report and information-services, we offering environmental water quality monitoring annual report and assisting with establishing environmental water quality monitoring e-annual report. During the executive process of this plan, it was requirement that the improvement and the necessarily processing program should be implemented by the contractors while a fault that might influence the quality of monitoring data was made from them. Moreover, from the executive result of this work, it revealed that the quality of data could be held effectively while personnel's technology and instrumental quality had been required rationally in advance. Generally speaking, besides of cooperating with this plan, if the contractors could strengthen self-checking even more, the promotion of the quality of monitoring data would be more efficient.