Analyzing ontological issues of an ethnicity, the authors examine the topic of myth and myth-making practices. A myth in itself is a changing phenomenon. The transformations of ethnic consciousness and cultural practices are largely related to this phenomenon. The authors note that at turning points of the history, ethnic consciousness, stimulating the process of cultural transformation, constructs an original world of the mythical notion that will support the ethnos’ survival and self-development strategy in the context of the social and cultural upheaval. Playing an important role in the processes of ethnos’ adaptation to the new, sometimes traumatic for the ethnic consciousness, historical events, the myth allows to retain the sense of ethno-cultural identity. Paying close attention to the proportion of rational and irrational-spontaneous in the ethnic consciousness, the authors show how, on the basis of ethnographic material, it is possible to discover and reveal the myth’s mechanisms of transformations. So, by the example of the people of Khakassia, the article shows the characteristics of the myth-making practices activated in critical conditions. The authors note that, while updating the historical memory, the social and cultural upheavals steer the ethnic consciousness to reconsideration of the history - real and/or mythological. This helps to solve the problem of socio-cultural mobilization and consolidation of the ethnic group. The study of the myth-making practices’ mechanisms permits the further fruitful development of the theory of myth.