The development of the concept of cost accounting of ecosystem services of forests in the context of the theory of natural-ecological accounting is presented, taking into account the characteristics of forests as object of national accounting and sustainable nature management.The main objectives of the study are to identify the need to distinguish between natural and environmental capital, to determine their relationship and differences; to show the expediency of identifying physical and cost indicators of ecosystem services, the accounting role of the timber reserve as a producer of ecosystem services. A method for cost accounting of ecosystem services based on the theory of reproduction and ecological rent is proposed.The results of the study are expressed in a concentrated form by the conceptual scheme for constructing a cost accounting for forest ecosystem services. The content of the value measurement of forest ecosystem services depends on their belonging to natural or ecological capital.