Key ecological functional areas refer to areas where the ecosystem is very important and related to the national or large-scale ecological security. At present, the ecosystem has been degraded, so it is necessary to limit the development of large-scale and high-intensity industrialization and urbanization in land space development in order to maintain and improve the supply capacity of ecological products. Key ecological functional areas belong to one of the two types of "restricted development zones" in the National Major Functional Area Planning. At present, 25 regions have been identified, with a total area of about 3.86 million square kilometers, accounting for 40.2% of the national territory. National key ecological function area takes the protection and restoration of the ecological environment and the provision of ecological products as its primary tasks, develops suitable industries that do not affect the orientation of the main functions according to local conditions, and guides the gradual and orderly transfer of the overloaded population. National key ecological functions are divided into four types: water conservation, soil and water conservation, wind and sand fixation and biodiversity protection.

The key ecological function areas focus on restricting development, not development, mainly restricting large-scale and high-intensity industrial urbanization development, but allowing a certain degree of energy and mineral resources development. Key ecological function areas can better protect the productivity of ecological products in such areas and realize scientific development by restricting development, which is consistent with the development direction of "ecological function protection areas" proposed by the Ministry of Environmental Protection.