The article investigates the problems of low life expectancy and high death rates in the regions of Siberian Federal District, as the barriers for the modern social modernization, basing on a comparative analysis of national averages, as well as in dynamics. By analyzing the data of Russian Center of Statistics and representative public opinion polls for the program “Socio-cultural evolution of Russia” of The Center for the Study of socio-cultural changes of the Institute of Philosophy of Russian Academy of Science the authors consider specific factors that explain the gap in life expectancy between the regions of Siberian Federal District and Russia as a whole. It is revealed that the main reasons for the lag of Siberia in life expectancy from Russian average are the factors of mortality from avoidable causes like tuberculosis, external causes (especially in men), for instance, coronary heart disease at a relatively young age. Currently, low life expectancy of the population in the regions of Siberian Federal District and especially high mortality of capable population prevent the accumulation of the demographic potential, being a major barrier for social modernization of Siberia. In this case, not only low life expectancy is the barrier, but mostly socio-economic conditions, preserving it at this level and affecting both the low birth rate and migration unattractiveness of the region.