The article considers the problem of population’s income inequality in the Russian Federation and detection of the factors affecting it. Population’s income differences demonstrate both intrinsic and unavoidable differences among individuals and their groups in terms of their participation in the social processes, and the governmental efforts aimed at reasonable and fair distribution of the national wealth among the citizens. The research objective was to identify the dynamics of the Gini index as acknowledged indicator for population inequality in terms of income and to analyze the factors defining such dynamics. The research was carried out based on the national statistical data. The authors detect close connection between the downturns in economy, especially decrease of the dynamics of average income per capita, and the level of population inequality in terms of income. However, contrary to expectation, the correlation is direct which means that during the periods of slowing of the income growth the values of Gini index being the avowed income inequality indicator also reduced. On the other hand, the authors point out that such connection exists only for time series. While studying the static populations’ income differences in various regions no correlation between the income size and difference values was found. Based on the research results the authors draw the conclusion about undesirability of violent fluctuations in the dynamics of the population’s effective earnings, as well as about justifiability of the efforts of national and regional authorities aimed at the improvements of the income policy.