<<Poverty and marginalization of population ("social bottom")>> based on recent studies reviews the scale and depth of poverty in Russia today as a social phenomenon. A classification of people categories is suggested who form "social bottom" of a society. Causes and factors are analyzed in detail to find out routes and scope of downward social mobility, as well as of existing and feasible impact by marginalizing on social fabrics combined with lacking attention to the above issues. A picture of Russian "social bottom" is, so author, urging for an elaboration of preventive measures program to render assistance to people affected by this social condition.