This paper is intended to introduce one aspect of the Qi philosophy of ancient China. First, the writer explores the philosophical import and historical influence of Zhuang Zi's hylotheistic views of nature. Second, the historical context of the development of Daoist thought is related to the Qi philosophy of Zhang Heng-qu, a master of Neo-Confucianism in the Northern Sung Dynasty. Through the interpretation of Zhang's term-the reaction between Tai-xu and Qi-we can understand the content of his thought as well as how he inherited and transformed Zhuang Zi's thoughts.