Abstract
Seonya theory(宣夜說) was one of the most important metagalaxy model in the ancient times. Unlike the other important metagalaxy model, it had the concept that the sky is not in the solid state but is just the infinite space which is full of gi(氣). But Seonya theory, though it had partially the superb academic thought, it had gradually become the forgotten thing among scholars in the ancient times. Since then, once forgotten Seonya theory was reconstructed again in Song(宋) dynasty, and Jangjae(張載) did the main role at that time. In the historical sequence like this, we need to take notice of one thing that "Hwangjenaegyeong(黃帝內經)" had worked on Jangjae as the origin of his sunya theory. So we also need to take notice of one thing that "Hwangjenaegyeong" is just a rare document that comprises the academic thought of Seonya theory which had once been forgotten in ancient times. Based on the historical situation like this, this study is focused on the idea that the discuss on the Jangjae's Seonya theory would be a good way to think of the cosmic theory of "Hwangjenaegyeong" and the theoretical thought derived from them. So this study will first look into the academic characteristics of Seonya theory of ancient times and of "Hwangjenaegyeong" and through the study on the academic characteristics of Jangjae(張載)'s Seonya theory, will also think of the significance of the thought of Jangjae's Seonya theory that would be some help to the research on "Hwangjenaegyeong".