Abstract:An evaluation indicator system was constructed from the aspects of economic, social, and ecological environments to evaluate the benefit of water diversion from the Yangtze River to Taihu Lake. With consideration of the fuzziness of boundary values of the evaluation criteria, the fuzzy set pair analysis assessment model was used to evaluate the comprehensive impact grade of the water diversion project on the intake area, and the assessment results were compared with those of the comprehensive indicator method. The Cronbach’s α coefficient was used to test the internal consistency reliability of the indicator system. To determine the indicator weight, game theory was used to integrate the subjective weight(the analytical hierarchy process method)and the objective weight(the entropy method). Thus, the relatively balanced comprehensive weight was obtained. With the methods mentioned above, the benefit of water diversion from the Yangtze River to Taihu Lake in 2014 was evaluated comprehensively. The assessment results of both methods show that the Yangtze River to Taihu Lake Water Diversion Project has had a significantly positive effect on the intake area. However, the fuzzy set pair analysis method, which used the fuzzy connection degree to describe the certainty or uncertainty of the evaluation object and evaluation criteria, can provide more information.