自然资源的价格应该相当于其边际机会成本。理论上，边际机会成本应该相当于利用一单位某种自然资源的全部成本。边际机会成本由三部分组成：边际生产成本、边际使用者成本和边际外部成本。边际使用者成本是指用某种方式利用一单位某一稀缺自然资源时所放弃的以其它方式利用同一个自然资源可能获取的最大纯收益。边际外部成本是利用一单位某一自然资源时给他人造成的没有得到相应补偿的损失。作为一种环境资源，环境自净能力也具有边际使用者成本。

The price of natural resources should be equal to their marginal opportunity cost(MOC).Theoretically,MOC is the whole cost of employing an unit of certain natural resource.MOC is made up of three parts:marginal production cost(MPC), marginal user cost(MUC) and marginal external cost(MEC).When we use an unit of certain scarce natural resource by some way,the maximal abandoned net benefit which may be gained from using the same natural resource by other ways is MUC. When we use an unit of certain natural resource,the Coverspending uncompensated loss that other people suffer is MEC.As an environmental resource,the self-puriflcation capacity of environment also has MUC.