The problem of colonisation of postglacial areas is deeply interdisciplinary, and when trying to approach to the description of the settlement pattern objectively ex-isting in the Final Palaeolithic and Early Mesolithic in a particular territory, the following aspects should be taken into account: high dynamic of the Late Glacial and Early Holocene natural conditions; the precise values of such vital parameters as the average temperature of the coldest month, the balance of precipitation and evaporation, the diversity of available natural resources in a particular territory; significantly different than at present, the configuration of land and sea, as well as the internal hydro network; general settlement picture for the macro-regions of the world, general cultural and demographic situation. Finally, the state of archaeo-logical study of the territory and the scientific discussion on the degree of legitima-cy of extrapolating conclusions based on modern ethnographic information about traditional societies to the ancient population of hunter-gatherers play a significant role in solving the aforementioned problem. The report is devoted to one of the as-pects of the problem of the south-eastern Baltic region colonisation: to the recon-struction of Late Glacial - Early Holocene natural conditions, as the basis and prerequisites for the settling of this territory.