Abstract: River ecosystem service function implies the natural environmental conditions and their effectiveness formed and sustained by the ecological processes of river ecosystem, and includes the two aspects of products and services. In this paper, 15 kinds of river ecosystem service function, including 6 kinds of products (water supply, fish resources, inland navigation, hydro-power, recreation, and culture and aesthetics) and 9 kinds of services (flooding control, soil and sand transporting, water resources storage, soil conservancy, environmental purification, CO₂ fixation, nutrient cycling, wildlife habitat supply, and biodiversity), were introduced, and the effects of dam-construction on them were analyzed. It was suggested that keeping well-balanced river ecosystem service function would be one of the essential factors in dam-construction decision.

Key words: Eriocheir sinensis, Gut, Chitin, Digestive bacteria