How to evaluate its ecosystem structure and function during the Twelfth Five-Year Plan period? According to the national main function zoning, the national key ecological function zone refers to the area where the ecosystem is very important and related to the ecological security of the whole country or a larger region. At present, the ecosystem has deteriorated, so it is necessary to limit the large-scale and high-intensity industrialization and urbanization development in the national spatial development in order to maintain and improve the supply capacity of ecological products. The key ecological functional areas and agricultural products producing areas belong to the restricted development areas in the national main functional areas. National key ecological function area has 25 regions, They are Daxinganling, Changbai Mountain, Altai Mountain Forest Ecological Function Zone, Sanjiangyuan Grassland Meadow Wetland, Zoige Grassland Wetland, Gannan Yellow River Important Water Source Ecological Function Zone, Qilian Mountain Glacier and Water Conservation Ecological Function Zone, Nanling Mountain Forest and Biodiversity Ecological Function Zone, Loess Plateau Hilly and Gully Soil and Water Conservation Ecological Function Zone, Dabie Mountain Soil and Water Conservation Ecological Function Zone, Guangxi, Guizhou and Yunnan Karst Rocky Desertification Prevention, Soil and Water Conservation in Three Gorges Reservoir Area, Desertification control in Tarim River, Altun Grassland, Hulunbeier Grassland, Horqin Grassland, Hunshandake Sandy Land, Grassland at the northern foot of Yinshan Mountain, Sichuan-Yunnan Forest and Biodiversity, Qinba Biodiversity Ecological Function Zone, Forest Ecological Function Zone on the Edge of Southeast Tibet Plateau, Qiangtang Plateau Desert Ecological Function Zone in Northwest Tibet, Sanjiang Plain Wetland Ecological Function Zone, Wuling Mountain Biodiversity and Soil and Water Conservation Ecological Function Zone, Tropical Rainforest Ecological Function Zone in the Central Mountainous Area of Hainan Island. Evaluation method of ecosystem structure and function in national key ecological function area: According to the material quality estimation of different types of ecosystem services, the dominant ecological functions and main auxiliary functions in this region were qualitatively and quantitatively evaluated. When necessary, the economic value of the leading ecological functions in this area can be evaluated. With the support of remote sensing (RS) and geographic information system (GIS) technology, the coefficient method is used for estimation. Through field monitoring and literature research, the quality coefficient and area of ecological functions of different ecosystems in the region are obtained, and then the quality of main ecological functions in the region is calculated. The function of soil and water conservation is measured by the difference between potential soil erosion and actual erosion. The water-holding function is calculated by the difference between the maximum water-holding capacity of soil and the wilting coefficient of soil. The flood storage function is mainly estimated by the precipitation intercepted by the ecosystem or the flood absorbed. The function of windbreak and sand fixation is estimated by the amount of sandstorm reduced by the ecosystem. The function of biodiversity protection can be expressed by the species and quantity of important national protected species, and the function of biodiversity protection in sea areas can be measured by fishery output.