Was the Wei-Jin Xuan-xue influenced by Buddhism when it came into being during the Wei and Jin dynasty? It is an unresolved question and difficult to answer for a long time. He Yan is the founder of the Zheng-shi Xuan-xue philosophy and On Wu- Ming is his representative work which reflected his early Xuan-xue ideology. The fundamental philosophical conception of the work is ＂nothingness＂ and this is just the same term used to describe the notion of ＂emptiness＂ by the Buddhistical classic. For this reason, the author discusses the Buddhism climate of the Chao's family where He Yan was entrust and grown up. Then he compares On Wu-Ming with the ＂emptiness＂ of the Chinese version of Buddhism classic and points out the identity and difference of the two concepts when they were used in their own setting. The author comes to conclusion as follows: It seemed that He Yan didn't understand the true meaning of ＂emptiness＂ of the Buddhism, but his theory was stimulated by Buddhism. He Yan's philosophy was transformed from the traditional cosmogony into ontology under the enlightenment of the Buddhism and at last Xuan-xue was formed and it set high value on ＂nothingness＂.