[Objective] The objective of this research is to evaluate comprehensive benefits of ecological engineering in the lake buffer zone in Zhushan Bay in Zhoutie Town, Yixing City, Jiangsu Province to quantitatively analyze the value of ecological conservation and to provide a basis and reference for the benefit assessment of ecological engineering in Taihu Lake basin and other watersheds. [Methods] Based on long-term fixed point observation of the ecological engineering construction in Zhoutie Town, we build an evaluation system from three aspects of economy, society and ecology. Indicators of evaluation system include water purification, water conservation, protection of biological diversity, air modulation, providing employment opportunities, research and education, social stability, leisure tourism, aquatic production and so on. Methods of indicators value evaluation are reference method, shadow project method, travel cost method, contingent valuation method, substitution method and direct market method. [Results] The comprehensive benefit of lake buffer zone ecological engineering in Zhoutie Town is 1.766 6 million yuan per year, including 1.255 5 million yuan per year of ecological benefits, 336.1 thousand yuan per year of social benefits and 175 thousand yuan per year of economic benefits, that means ecological benefits > social benefits > economic benefits. The result of single index value comparison found that the value of water purification is largest, up to 605.2 thousand yuan per year. The following is the value of air modulation, which is 471.5 thousand yuan per year. [Conclusion] Ecological engineering in Zhoutie Town effectively improved the aquatic environment of lakes. The ecological benefit is most remarkable, which is in accordance with the principal that priority of ecological value is in priority in ecological engineering.