[Objective] The ecological system service value of wetlands in Loess Plateau was evaluated scienti-fically in order to preserve the wetland ecological service, and to formulate a complete ecological conservation and compensation policy in Loess Plateau.[Methods] Based on fundamental data and other relevant data in Qianhu National Wetland Park, Shaanxi Province, direct and indirect usage values, including air regulation, water storage and retention and others 7 items of ecosystem service values were divided into estimated by methods of market-price, shadow-price and carbon tax, and so on.[Results] Among all the ecological system service values, air regulation service had the highest value which accounted for 87.5% of total ecological system service value; followed by cultural use, which accounted for 5.73% of total service value. The water purification service had the lowest value, which only counted for 0.09%. The system service value went up about 7.90×10⁵ yuan per hectare, which was smaller than that of Hechuan Wetland, another wetland located in Shaanxi Province.[Conclusion] The total value of the ecosystem service functions were about 3.30×10⁸ yuan. The indirect use value of ecosystem service accounted for 90.5%, which was markedly higher than that of the direct use value (9.5%).