Abstract: Globally, the existing protected areas and Aichi Target 11 are not enough to slow the decline of biodiversity. As a result, there is an urgent need to set a higher target for protected areas and further expand the protected areas system. In 2009, the Nature Needs Half (NNH) initiative was launched by the WILD Foundation, which called for protecting at least 50% of the Earth’s land and ocean areas in an interconnected way. This paper systematically reviews and introduces the background and development of the NNH initiative. The main content of the NNH initiative is analyzed in three phases including its forming process, formal proposal and recent development. The feasibility of the NNH initiative is further discussed from the perspective of science, policy and practice. This paper also suggests China to actively participate and play a bigger role in the NNH initiative and Post-2020 Global Biodiversity Framework.