To calculate the ecological externalities of cultivated land resources comprehensively and accurately is the basis of the ecological compensation for cultivated land protection. Cultivated land resources not only have positive ecological externalities, but also have negative externalities, such as the agricultural non-point source pollution, the soil heavy metal pollution and other environmental costs, therefore, when calculating the ecological externalities of cultivated land resources, the ecological benefits and the environmental costs should be fully considered. In this paper, the positive and negative ecological externalities of cultivated land resources in Nanjing city are calculated by the method of the unit area equivalent factor and the resource and environmental economics. It is shown that the ecological service of cultivated land resources in Nanjing city in 2014 is worth ￥55.08×10⁸; the negative ecological service value of cultivated land resources is ￥9.23×10⁸; the total value of the ecological compensation quantity is ￥45.85×10⁸, accounting for only 2.59% of the revenue, which does not constitute a financial strain. The calculation of ecological externalities of cultivated land resources provides a basis for correctly understanding the ecological benefits and environmental problems in the use of cultivated land resources and a basis for the development of ecological compensation measures.

cultivated land resources  /  ecological service  /  environmental costs  /  ecological compensation  /  Nanjing city