The article is concerned with the issues of the ethnic migrations impact on the ethnic composition of population in the countries of Central Asia. The period after the collapse of the Soviet Union and up to the present day was chosen for the research. Migrations between Russia and Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan affected the ethnic makeup fundamentally during that period. As a result of intensive migration processes the number and proportion of title nations increased in the countries of Central Asia. The proportion of Russians, Ukrainians, Germans and other nations decreased sharply. Kazakh, Kyrgyz, Tajik and Uzbek Diasporas are formed in the Russian Federation. The information about thenumbers and settlement of the nations in Russia and in Central Asia is provided in the article.