The process of harmonization of economic and environmental principles of nature management is to identify areas of interaction and optimize the parameters of interaction. One of the elements of the harmonization system is the process of quantifying ecosystem services generated by natural ecosystems. The importance of integrating the quantitative assessment of ecosystem services into the decision-making process on the nature of environmental management is due to the process of integrating various ecosystems and the flow of ecosystem services they generate into the global economic system. Several methods have been developed to quantify ecosystem services that successfully cover almost the entire range of ecosystem services provided by different ecosystems. The purpose of this article is to describe the existing methods for quantifying ecosystem services. The author notes that when choosing a method for assessing ecosystem services, the researcher must take into account a combination of various factors influencing the results of the assessment. When choosing in favor of the reliability of economic methodology, the researcher will be forced to abandon the analysis of all parameters of the ecosystem service. Each of the described methods for quantifying ecosystem services has both Advantages and disadvantages. The process of choosing a method of quantification can be optimal if the goals and subject of quantification of ecosystem services are correctly determined.