Abstract:A river ecosystem comprises stream channels and adjacent riparian zones. It provides some significant ecosystem services through diluting pollution concentrations and purifying stream waters. Therefore, studies on the self\|purification capability of a river ecosystem are critical for ecosystem health assessment and environmental management. Two major research approaches have been developed to study the river ecosystem structure and services, with one focusing on the use of water quality models to assess the self\|purification capability of a river ecosystem and the other studying the roles of riparian vegetation buffers in purifying stream waters. Based on extensive literature reviews, we have identified several areas that need further research. Firstly, more research should be carried out to investigate how terrestrial landscape heterogeneity and river channel morphodynamics could affect the self\|purification capability of a river ecosystem. Secondly, more emphases should be paid upon the methodology development that can enhance environmental parameter extraction for implementing water quality predictive models in complex landscapes. Lastly, a significant area for continuing research is the systematic study on non\|point pollutants transporting from land to water and within stream waters and the resultant spatio\|temporal characteristics of the self\|purification capability of a river ecosystem; such a study can provide useful insights for river ecosystem assessment and management.