On the basis of the fundamental principle of analytical hierarchy process(AHP), first of all, an intex assessment system on ecological footprint of the impact of a reservoir on river ecological service functions is established, and then, the weights of every index are determined by AHP. The Danhuofan Reservoir in Fushun is taken as an illustration, the aggregate assessment on the influence of the reservoir on river ecological service functions is carried out. At the end, the mentioned above model is applied to quantitatively calculate four-item ecological footprints and 3-item ecological demands of the Danhuofan Reservoir.