本文旨在探討「精氣」概念在《黃帝內經》形神結構中所蘊含的理論意義。論文首先從原始的「物精信仰」一窺精氣思想的雛形，其次從《管子．內業》等四篇的「精氣」思想，探論其宇宙觀與修養論；此應是後世精氣思想重要的理論源頭。在《黃帝內經》的形神結構方面，分別從其先、後天精氣圜道相生的生理機制，及其以「精氣」概念為核心的形神結構，探論其「精氣」思想的理論意義。論文的最後參酌《老子》談「精」概念的相關篇章，合諸前述《管子．內業》等四篇的精氣論與《黃帝內經》的養生思想，探論《老子．二十一章》：「其精甚真，其中有信」所指的「精氣」概念中可資信驗的「信息」意義。

This article aims at exploring the theoretical significance of the concept of “essence Qi” in the body-spirit structure of Huangdi Neijing. This article starts with the primitive belief on essence qi in everything to have a glimpse of the embryonic form of the thought on essence qi. Later the researcher tries to discuss the universal view and cultivation through four classic works including the Chapter Thirty-six, Thirty-seven, Thirty-eight, and Forty-nine of Guangzi, which are believed to be the important theoretical source of essence qi thought. As to the spirit-body structure of Huangdi Neijing, the researcher deliberates the theoretical meaning of essence qi via its physiological mechanism of mutual generating circle of nature and nurture, as well as its body-spirit structure with essence qi as the core concept. Finally, the article collates Laozi’s chapters on “essence”, and Guangzi’s four chapters on the theory of essence qi as well as the health preservation thought of Huangdi Neijing, to explore the idea “The essence is authentic, within which there is the information” in the Twenty-first Chapter of Laozi, and deliberate the meaning of testable “information”.