Mastering Oneself（Ke-ji）and Returning to Propriety（Fu-li） as Perfect Virtue（Ren） contains basic categories of Confucian ideological system and it is the key to master ideas of Confucius.Modern and contemporary off-springs have never stopped researching this system but are always in dispute.Ke-ji means cultivating and mastering oneself.Li could mean either proprieties in the Zhou Dynasty，or general rituals and norms in social context.Ren means morality and rational thinking in human relations.Ren can come either after or before Li；they can either integrate with each other or depart from each other.It is quite disputable about whether this is research of politics，sociology or ethnics.Even historians and philosophers diverge in their research methodology.As texts for research，the Analects of Confucius and Zuo Zhuan also vary in quality.In future，integrated research from various perspectives with case study should be emphasized.