Wu Gang (), formerly romanized as Wu Kang and also known as Wu Zhi in some sources, is a figure in traditional Chinese folklore and religion. He is known for endlessly cutting down a self-healing osmanthus tree on the Moon, a divine punishment which has led to his description as the Chinese Sisyphus. In modern Chinese, the chengyu "Wu Gang chopping the tree" (; wúgāng-fáguì) is used to describe any endless toil. The specific reason for his situation has varied in the sources, but Wu Gang's story dates back to at least the Tang dynasty.
An origin myth for the lunar phases was that a great forest or great tree grew there, swiftly growing and losing leaves and blossoms over the course of each month. After the expansion of the Chinese cultural area south of the Yangtze during the Qin and Han dynasties, the lunar trees became associated with the fragrant and white-blossoming Osmanthus fragrans. Thi