River ecology is a vital field in limnological research, and several new theories and methods have been developed and used in the study of lotic systems. In this article, a summary of these new theories was introduced, which includes river continuum concept, ecological water consumption of river ecosystem, services and health of river ecosystem, ecosystem management, and watershed ecology. The authors suggested that the research of river ecology should be carried out on the scale of watershed, and that the combination of ecosystem health and ecosystem services could be the key point in the sustainable development management of river ecosystem. Seeing that there are few studies in this area in China, relevant research should be conducted as soon as possible.