The present paper reveals the cases of the Lithuanian and Russian language interaction. The examples are based on all language strata: phonetics, lexicology, morphology, and syntax in the oral and written modes by the Lithuanian and Russian students. Those stratum are affected by the sociolinguistic situation in Lithuania: the demographical composition revealing the different conditions of the contrasts in both languages, the status of the Lithuanian language as the state language, the functional distribution of the both languages (native and non-native), the processes of emigration and immigration, the reduction of the Russian language functioning, and the increasing influence of the western languages. The sociolinguistic interpretation of the phenomena is presented as well. Not only the differences between the languages, but also the sociolinguistic factors (i.e. an intensity of the both language usage, the linguistic experience in the professional area, etc.) are highlighted. The method of correlative analysis was applied in the present study.