ENThe notion of 'interference' in linguistic literature is usually treated as deviation from the norm or system of the second language under the influence of the native language as dieconsequence of biligualism or language contacts. However, the exploration of the reverse process, i. e. the influence of the second language on the native language, is also important That is why the study of the pecuharities of bilingualism of the Russians in Lithuania is of; paricular interest. The analysis of acoustic characteristics (formant structure and duration) of the Russian vowels in the pronunciation of the Russians in Lithuania has helped to disco\ei some peculiarities in it mat are due to the influence of the Lithuanian language. According to the juxtaposition of the vowels in the acoustic space and the correlation between die frequencies of the first two formants, the analysed vpwels are near to die ąllophones ol" the Lithuanian vowels than to the normative Russian vqwels. According to the duration of the vowels, they occupy an intermediate position between the normative Russian vowels jud the short Lithuanian vowels.