The culture of ducks in rice fields is a long-standing traditional integrated farming practice in China. There has been a wide variety of studies on ecological and economic benefits from raising duck in rice fields, such as decreasing harmful pesticides and chemical fertilizers, a high efficacy in nutrient recycling, and high and diversified production. To further explore benefits relevant to humans from the rice-duck integrated farming system, the ecological services function such as agriculture productions, gas regulation, water conservation, soil organic matter accumulation and main nutrient elements maintenance were identified and analyzed on the basis of principles of ecological economics and relevant theories of value ecosystem services. Assessment approaches such as the law of cost, opportunity costs and project law of the shade were applied to measure services function value of the rice-duck ecological system. Results showed that total ecological services value of the rice-duck farming system was roughly 18,104.82 yuan per hectare, about 15.64% higher than conventional rice cropping system. For the rice-duck farming system, agricultural production and gas regulation function value was 6,720 and 5,928.72 yuan per hectare, accounting for 37.12% and 32.75 % of the total ecological services value, respectively. Water conservation function value was found to be the lowest, merely accounting for 14.16% of the total. Soil organic matter accumulation and main nutrient elements maintenance services amounted to 2,892.40 yuan per hectare, about 3.2 times of that in conventional rice farming systems. The value of environmental regulation services, comprised mainly of gas regulation, soil organic matter accumulation and main nutrient elements maintenance, was 11,384.82 and 9,885.62 yuan per hectare for rice-duck and conventional farming systems, respectively, representing about 1.69 and 1.84 times more than agriculture production value alone. It can be concluded that paddy rice culture provides not only the production of grain but also significant environmental regulation services. Effective in controlling greenhouse gas effects as well as conservation of soil fertility and quality, duck raising in rice cropping fields could improve the ecological and economic benefits of the paddy rice system. Even though certain disagreement regarding the environmental and economic value of agro-ecosystem services exists because of the lack of evaluation methods and variations in the cropping system, this study can be helpful in decision making for improving sustainable rice production technologies, strategic plans development and regional agricultural development policies.