This chapter elaborates on the international and domestic backgrounds of China’s ERLs delimitation. Internationally, against the grim global ecological protection situation, China actively responds to international calls for ecological conservation. Domestically, ecological civilization construction has been elevated to an unprecedented height, and delimiting ERLs is a key measure to address environmental issues and achieve sustainable development. It clarifies that the goal of ERLs delimitation is to fully protect the most important natural ecosystems, unique natural landscapes, the finest natural heritage, and areas with the richest biodiversity. This aims to realize large-scale, integrated protection of important natural resources, ecological spaces, rare and endangered species, and their habitats, provide ecological support for high-quality development, and contribute Chinese solutions to global ecological protection.