This chapter systematically reviews the work process of ERLs delimitation, from the initial proposal of the concept to its gradual promotion nationwide. It introduces the working mechanism, including collaboration among multiple departments such as the Ministry of Natural Resources, the Ministry of Ecology and Environment, and the National Forestry and Grassland Administration, as well as top-down and bottom-up coordination with local governments at all levels. It explains that the delimitation follows principles of strengthening coordination, prioritizing protection, seeking truth from facts, and integrating delimitation with management. Based on the results of the Third National Land Survey and assessments of resource and environmental carrying capacity and land space development suitability, multiple rules are formulated to properly resolve spatial conflicts, such as methods for coordinating contradictions between permanent basic farmland, commercial plantations, major construction projects, and ERLs.