The Qi-based Theory in Yi Zhuan and Zhuangzi's Tao-based theory are two distinctive theories in the pre-Qin period. The author of Yi Zhuan uses Yin (陰) and Yang (陽) to explain the creation of all things , and then uses the concepts such as Yi (易), Tao (道), Shen (神) to interpret why Yin (陰) and Yang (陽) are capable of generating all things . The cosmology in Yi Zhuan is systematic and logical, but its ontology is slightly rougher compared with Zhuangzi. Zhuangzi's theory, which is constructed by "Tao is Continuous", "Tao has no boundary", "Tao is not symmetrical" and "Creator is not entity", is systematic and logical at the theoretical level, representing the highest level of philosophical speculation in the pre-Qin period. Some concepts in Yi Zhuan are similar to those in Zhuangzi and Laozi, but they are significantly different in the core thought and humanistic purport. There is no doubt that Yi Zhuan belongs to the Confucian works.