This paper is mainly on the epistemology of 『Dodeok-gyeong(道德經)』 and 『Hwangje-Naegyeong(黃帝內經)』, and the relation of each other. Amog the conclusions, following things are worth mention. The point of 『Dodeok-gyeong』 can be said as the epistemological "Do(道)". When it expressed as something, it cannot be the original form. This principle can be applied to 『Hwangje-Naegyeong』 in the flow of Gi(氣) and in the property of movement of Eumyang-Ohaeng(陰陽五行). In 『Dodeok-gyeong』, the notions of the relativity of all things, come out as interpromotion and interacting. It can be related to the typical etiology and pathology of the Eastern medicine. In 『Dodeok-gyeong』, the emphasis on woman which represents the 'Eum' also emerged well in 『Hwangje-Naegyeong』. 『Dodeok-gyeong』 emphasize on the relative value of the contrasted things. In the Easten ideas, the smallest thing can be the same as the largest thing with the exception of comparison of each other. As the same way, the human body can be the small cosmos, and the Heaven and human beings correspond to each other.