Abstract: The ecosystem ecology of the rapid-flowing stream in North Temperate was investigated over a period of six-years field studies. Some ecosystem level properties such as component parts, structure, energy flow, material cycling were determiaed and so were the biological environment and the pathway of energy transfer as well as the energy flow frame. The turnover rates of different trophic levels were calculated in biomass. Dynamic models of oxygen changes and of hydrological cycling were then established. The food chains and web were divided dependent upon the trophic relationships of the living organisms, which might be separated into three groups: producer, consumer and decomposer by the classical theory, but in fact each with function of production, consumption and decomption. So this paper suggests that producer, consumer and decomposer should be replaced with productive processes, consumptive processes and decompositive processes respectively.