Hu Yin (ft. 848), a Daoist priestess, physician, and medical theorist active in the first half of the ninth century China, composed one work on Daoist longevity technique and medical theory titled Huangting neijing wuzang liufu buxie tu (Chart of the Tonification and Purgation of the Five Viscera and Six Receptacles according to the Inner Landscape of Yellow Court Scripture). By elaborating the Daoist classic Huangting neijing jing, Hu Yin's work describes the spirits, physiological function, pathological mechanism, and therapeutic methods of six viscera, namely heart, lungs, liver, spleen, kidneys, and gallbladder, and offers detailed instructions on longevity techniques and medical treatments for nurturing the viscera, such as breathing exercise, gymnastics, and dietetics. These descriptions and instructions had exerted profound influence on the later development of Daoist inner-cultivation and inner-alchemy theories, as well as traditional Chinese medical and nurturing-life theories.