This study aims to review the short history of language situations in Belarus and to examine the changes and consequences of the language policy during the Soviet period and 4~5 years after the independence. 25 years after the dissolution of the Soviet Union, Russian is the national and most important language in Belarus, unlike in other post-Soviet Republics. As a matter of fact, 100% of Belarusians can speak Russian and approximately 5% of people can speak Belarusian fluently. In Belarus, the Russian language holds the status of the state language due to its cultural and historical background, rather than a friendly relationship between Russia and Belarus. More than 80% of the residents are virtually Belarusian-Russians in every public sector and personal activity. Russian is a mandatory language of all secondary schools in addition to the Belarusian. Moreover, the Russian-speaking population of Belarus is treated not as foreigners, but as members of the state, and is seen as part of the state-forming nation. The reason is that the indigenous titular ethnic Belarusians are officially considered to constitute the Republic of Belarus, and Russians are also included as a state-forming nation in Belarus.