揚雄與王充是漢代重要的思想家，他們打破了自董仲舒以來的意志天為主宰之觀念，認為自然才是決定一切的存在，並建立以自然為命題的人性論。二人分別提出「善惡混」與「有善有惡」的人性說。本文從善惡的價值判斷、根源、可變因素等問題，來探討揚雄與王充人性善惡的本質與現實意義。從修養功夫來說明成德之途徑，二人皆以道德與才智兼具為其理想之人格。

Both YANG Xiong and WANG Chong are the major philosophers in the Han Dyansty. They destroyed the concept, ideology heaven dominates everthing, which described from Dung Zhung-Shu and believed that existence of whole world is resolved by nature. Moreover, they established thought on human's nature based on nature. They have addressed the thought on human's nature of “mixing righteousness and evil” and “proving with righteousness and evil” individually. This text will probe into human's natural and the meaning of reality from judge by the value, source and variety of good and evil. By the way of accomplishing private morality by cultivating one's moral character, they both being possessed of morality and ability and wisdom, are provided with ideal moral in tegrity.