针对河流功能认知不深入的问题，从系统论观点出发，对河流功能本质进行了探讨，服务于河流功能的可持续利用，以期推动河流功能理论发展。研究表明，河流功能是河流系统与其环境相互作用过程中表现出的能力和效用，是河流系统发挥的有利作用，由河流系统结构决定，通过河流系统中的物质流、能量流和信息流实现，通过对自身及外部环境需求的满足表现，通过采取局部利益服从整体利益和低层次需求优先原则权衡对河流的需求实现河流功能和谐。

In order to deeply understand river functions, the essence of river function is discussed from the system theory for its sustainable utilization and it is expected to promote theoretical development of river function. The results show that, river function is the ability and effectiveness in the interactional process between river system and environment, it is determined by the structure of river system, achieved through the material flow, energy flow and information flow in the river system, and expressed through meeting demands for river own and external environment. River functional harmony was built by using principles that includes the local interest obedience overall benefit and the lower level needs priority.