The river ecosystem provides significant ecosystem services which are the bases of watershed sustainable manangement. Rivers are the natural ecosystems that humans and other living things depend on for survival. Throughout the history of human civilization, river ecosystems have played an important role in the origin and development of human society. Therefore, river ecosystems and human systems are integrated and interacted. By reviewing the current studies, we concluded that the definition of river ecosystem health was determined by the river itself, human demands, and management targets. The influencing factors of river ecosystem health included anthropogenic activities, land use, river habitat, water quality, water quantity, and climate change. Based on these factors, several assessment methods have been developed, including indicative species, integrated index, and mathematical model. Last, we conclued the main issues needing further research, such as the understanding of concept, assessment criteria, and land-water coupling. We must realize that healthy river ecosystems can not completely eliminate the intervence of human activities, which is not a zero-sum game. Therefore, we need to pay attention to the river health to guide river basin managers and protect river ecosystems. The further research should be enhanced by judging the river ecosystem health from a comprehensive view. The health of river ecosystem needs a healthy watershed. As an ecological corridor, river habitat should be investigeated by combining the local and regional influencing factors. The trans-regional comparsion of rive ecosystem health should be developed by a coherent criterion from the water sampling, data analysis, and result assessment. In addition, new data sources can bring benefits for the assessment of river ecosystem healthy, including remote sensing data, spatial data, and other big data.