The purpose of the paper consists in the analysis of ethnic adaptation as historical phenomenon. As such, the interaction of peoples with the natural and social environment is considered. This intention is determined by the urgency of the problem related to the fact that peoples, being physical reality by their genesis, are socially structured in the modern world in more than 250 independent states and in about 5 thousand large and small ethnic communities. Research problems are in the plane of studying of historical experience, that from aspects, which is the concentrated expression of ethno adaptation social practice in the context of functioning of the people in the natural landscape surrounding them. The method of studying the problem posed is, first of all, the ecological-historical method. According to it, the environment includes both natural and man-made components. At the same time, the natural landscape and the environment are different categories. The environment is the result of the activities of both the person and entire nations. Nature is an inert element in the environment, not a necessity, but only an opportunity that is realized or not realized. The person as a representative of an ethnic community, a carrier of a certain ethnic culture and psychology is its active element, a host of possibilities. The results of the study show that ethno-adaptation is expressed not only in the adaptation of the people to the natural landscape, but also the landscape to the ethnos and therefore it serves as a kind of “adapter” in the interaction of ethnic communities and the natural environment. The negative consequences of ethno-adaptation practice are periodic disruption of biological and demographic equilibrium, the presence of significant numbers of relict (minority) peoples on the modern ethnic map of the world and the possible premature disappearance of some of them. Results of a research can be applied when carrying out further researches on ecological history, ethnic ecology and historical ethnology, writing of the generalizing works on these problems.