Huangdi Neijing (simplified Chinese: 黄帝内经; traditional Chinese: 黃帝內經; pinyin: Huángdì Nèijīng), literally the Inner Canon of the Yellow Emperor or Esoteric Scripture of the Yellow Emperor, is an ancient Chinese medical text or group of texts that has been treated as a fundamental doctrinal source for Chinese medicine for more than two millennia. The work comprises two texts—each of eighty-one chapters or treatises in a question-and-answer format between the mythical Yellow Emperor and six of his equally legendary ministers.