The theories of “Qi ascending and descending” and “interior-exterior relationship between lung and intestine” were both recorded in Huangdi’s Internal Classic, and both played a vital role in the system of Traditional Chinese Medicine(TCM). Besides, they are widely practiced in TCM clinic. As a representative pair of organs that share a interior and exterior relation, the qi ascending and descending between lung and intestine has unique features. That the lung and intestine are close to each other could evidence their interior-exterior relationship, that their relationship contributes to ones life, and the Qi movement between them are the basic mechanism of their relationship. This paper aims to reveal the connotation of the correlation between lung and intestine from the following aspects: Qi ascending and descending of lung, those of intestine, and their correlation.