The article deals with the lexical changes that occurred in the Belarusian language within the 1930s. Books many times printed in the 1930s were the source of the study. Let alone that a certain stability in the lexicon of the Belarusian standard language was achieved by the end of the 1920s, one can observe a landslide of many norms previously used in editions of 1933 and later on. These changes happened against the background of the party-state activities in the field of the corpus planning of Belarusian (the “Results of the Discussion on Linguistics” resolution of the bureau of the Central Committee of the Belarusian Communist Party of 1930, the “About changes and simplification of the Belarusian orthography” resolution of the Council of People’s Commissars of the Belarusian Soviet Socialist Republic of 1933, language cultivation campaign etc.). Changes mostly concerned Polonisms and words identical to Polish, as well as unique neologisms and colloquial Belarusian words. Mainly Russianisms and words with Russian cognates replaced them.