The differentiation of ethnology, cultural anthropology and social anthropology, the three important terms in ethnology and anthropology,usually creates certain obsessions to beginners of the subject. The academic circles generally think that the meaning of the three terms is roughly the same,but there are some minor differences, and there is a kind of "interlinked" relationship among them. Not only are the emergence and dissemination of the three terms related to historical and cultural traditions of different countries and regions, and they also closely linked to the academic tradition in different countries and academic preferences of scholars. Therefore,we should take full account of the national conditions in the study and absorb the academic ideas of other countries,and strive to develop the academic route suitable for the historical and cultural traditions of China,so as to enhance the international influence of Chinese ethnological research.