Abstract: The concept of “distinguishing between different ethnic groups” discussed in the Book of Changes was a necessary prerequisite for the interaction and integration of various ethnic groups in ancient times.However,there have always been various interpretations of its original meaning,among which the interpretation of “class ethnicity” as “distinguishing differences to achieve similarities” and the interpretation of “clan” in “class ethnicity” as a clan or a clan of clans is one of the more appropriate interpretations.Distinguishing related clans and seeking similarities while preserving differences,this kind of “clan like” thing had already been carried out as early as the Five Emperor's era.It is said that during the reign of Shun,there was a “separate birth (surname) classification”.During the reign of Yu,land and surnames were granted based on the virtues of the clan.The situation of ethnic groups in the Shang Dynasty is mainly reflected in the divination about “bi”(“比”).The ethnic groups of the Zhou Dynasty tended to deepen and refine,playing a positive role in maintaining the order of the patriarchal society and strengthening clan unity.During the Spring and Autumn Period and the Warring States Period,the upper class aristocrats attached great importance to “membership”,while the lower class laboring masses gradually became the “household registration” of the state,all of which had the influence of “class”.“Clan like” is an important concept and method of state management of society in ancient times.Through the historical development of “ethnic groups” in the pre Qin period,its important significance in the development of ancient Chinese social structure can be demonstrated,deepening the understanding of the exchange and integration of various ethnic groups in the formation process of the Chinese nation.