Abstract: The subject of this research is the transformation processes in resettlements of the Semeiskie Old Believers in the Western Transbaikal Region throughout the XX and XX centuries. The authors examine the population dynamics in the Old Believer settlements of the Western Transbaikal Region. A conducted geographical chart traces the population decline from the rural areas into the district administrative centers. The three time periods are determined: pre-Soviet, Soviet and post-Soviet, marking the historical events that affected the resettlement of the Semeiskie of the indicated region. The authors consider the transformations within the system of resettlement of the Semeiskie, trace the population dynamics among the Old Believers, as well as the development of localities within the limits of the main range of their resettlement. The scientific novelty consists in the fact that this article is first to reveal the discussed topic from the perspective of cartographic analysis. The author observe a high natural population increase in the first half of the XX century, the expansion of Old Believer communities in the poorly inhabited territories. By the end of the XX century, the population sized in the district centers has increased due to the inflow of population from the surrounding rural areas and villages, so the previously inhabited territories have become neglected. At the present time, the demographic development and resettlement of the local Semeiskie communities and Old Believers’ descendants do not differ from the national urbanization trend.