In countries of the former Soviet Union concentrated almost half of the modern Ukrainian diaspora, particularly in the Russian Federation is home to the most numerous Ukrainian diaspora in the world. A reason of appearance Ukrainian diaspora in these countries was voluntary and forced migration, and in Belarus, the Russian Federation and Moldova - factor of state delimitation. As a result of the census of population, which took place in the former Soviet Union after 1989, established changes in the numerosity of Ukrainian diaspora and its settlement. Given the specificity of the countries that were part of the Soviet Union, can be identified there are four groups of countries: the Baltics, Central Asia and the Caucasus. The fourth group consists of Belarus, Russia and Moldova, where part of the Ukrainian diaspora are autochthonous population. Compared with other countries in the Baltics countries dynamics of decrease number of Ukrainians is lower. In spite of membership of these countries in the EU, processes of modern Ukrainian labor migration, Ukrainians are excluded from active political and public life in these countries. In Central Asia after 1989 found that the rate of decrease of Ukrainian diaspora very high because of low economic development, political situation in the region, Ukrainian integration into the Russian diaspora, natural decreases. In Armenia, Georgia and Azerbaijan because of military conflicts, revolutions and low living standards number of the Ukrainian diaspora is negligible. Beside this on the Ukrainian diaspora has influence linguistic, cultural and religious distance from the titular ethnic groups. In Belarus, the Ukrainian diaspora lives mainly in Brest region and major cities. Ukrainian diaspora in Moldova is living mainly in the northern parts of the country and Transnistria. In the Russian Federation it is the Ukrainian ethnic territories and major cities, in which directed the flows of Ukrainian labor migrants. The reasons for reducing the number of Ukrainian diaspora were military conflicts, low life, and the unstable political situation that led to the re-emigration to Ukraine or other countries. Among other reasons, it should be noted assimilation, a natural decrease in the number of Ukrainians. [ABSTRACT FROM AUTHOR]