Ecological protection redline delineation aims to protect the natural ecological systems, which support human economic and social sustainable development, and constantly improve ecosystem services through the implementation of strict control measures. Based on the Environmental Protection Law, and re- lated research and practices in China, we make the concept of ecological protection redlines clear, and pre- sent potential formation (including key ecological function areas redlines, ecologically sensitive or fragile areas redlines and forbidden development areas redlines). Furthermore, we confirm concrete forms of all kinds of redlines. Key ecological function area redlines are divided into land functional areas (including wa- ter source conservation areas, water and soil conservation areas, windbreak and sand-fixation areas and bio- diversity maintenance areas) and ocean functional areas (including marine aquatic germplasm resources ar- eas, important coastal wetlands, special protection islands, concentrated distribution area of rare and endan- gered species, important fishing waters, etc.), ecological sensitive or fragile areas redlines (divided into land ecological sensitive or fragile areas, including land desertification area, soil and water losses areas , rocky desertification areas and soil salinization areas and ocean ecological sensitive or fragile areas, including coastal natural coastline, mangrove forest, important estuarine, important sandpaper coast, sand protection waters, coral reef, sea grass beds, etc.), while forbidden development areas contain nature reserves, world ·生态保护红线专题·