The main purposes of this research include establishing an assessment system of river water natural purification engineering, assessing the operation and maintenance status of 26 sites, drawing up a reference manual of designing and managing constructed wetlands for civil use, following up the natural purification effect of the pilot scale contact gravel bed at Guandu Nature Park, and holding two educational conferences. (1). Accomplish “Water Natural Purification – Designing and Managing Constructed Wetlands Reference Manual.” This manual consists seven chapters include design, operation, maintenance, and management, and is giving referential information of constructed wetlands for domestic environmental protect bureaus and other relevant civil agencies uses. (2).Assessing operation and managing status of 26 sites and establishing self-checking list. About the result of assessment, the category of free water surface constructed wetland gets 84.38 points, contact oxidize gravel bed gets 79.60, and overland flow gets 84.90. (3).Compare the economic effect with swage plant on wastewater treatment, free water surface constructed wetland is $0.21 NTD/CMD cheaper on primary treatment, $14.41 NTD/CMD on secondary treatment, and $20.71/CMD on tertiary treatment. (4). The research of gravel bio-film de-pollutant mechanism held on the pilot scale contact gravel bed at Guandu Nature Park reveals the most common bacteria genus founded within bio-film are Cyanobacteria and Chroococcidiopsis, which are common in high N-concentration water and do help degrading organic N. (5). To enhance the technique of river water natural purification engineering, and improve the communication between official and civil experts, two educational conferences were held at June 8th (Taipei) and October 31st (Kaohsiung). Through inviting scholars from Japan and Taiwan, about 218 people attended these conferences and shared relevant experiences.

on-site treatment,a handbook on managing and designing constructed wetlands,maintenance quality control