Wang Bi, Xiang Xiu and Guo Xiang were no doubt the most significant figures of "Wei-Jin-Xuan-Xue". In the main theme of "Wei-Jin-Xuan-Xue", Wang Bi's philosophy was mainly derved form the though of Laozi. "The Zi Ran and Ming Jiao "(Spontaneity and Virtue) -was about the ontological problem of "non-being".Since "Zi Ran "(Spontaneity) is the Natura Naturans, "Ming Jiao" is the Naturata, therefore "Zi Ran " (Spontaneity) and "Ming Jiao" (Virtue) became unified. As for Xiang Xiu and Guo Xiang, whose philosophy was mainly derived from the thought of Zhuangzi, their main concern was the ontological problem of "the unity of being and non-being". Therefore, and again, "Zi Ran and Ming Jiao"became unified.This paper discusses the characteristics of "Wei-Jin-Xuan-Xue", and hence presents a key to interpreting this theory in a consistent and significant way. At the same time, it also compares this theory with Confucianism, Daoism, Idealism and Existentialism.