In the article, current situation in the study of the role of ethnic factor in political science and in some other related disciplines is discussed. As it may be concluded from the author’s examination of publications of Russian and foreign scholars, blanks still remain in the field of theoretical investigation of this problem. It is demonstrated, in particular, that basic concepts used in the discussions on the subject (ethnos, ethnicity, nation etc.) are not clearly defined. As it is pointed out, application of the ethnos theory by S.M.Shirokogorov and of the theory of chrono-political dimension of politics by M.V.Ilyin as well as of some recent achievements of political anthropology, may help improve the situation.