The of aim of the present study was the estimation of the influence of proficiency level of the second language on activation patterns of language areas. 30 volunteers participated in the experiment (15 females and 15 males) from 18 to 40 years of age. Mean age was 28 years. All participants were divided by linguist into two groups according to their proficiency level of the foreign language: high proficiency group (HP) and low proficiency group (LP). Block design method was used in the performed experiment. The experimental task was speech production in the form of sentences, the control tusk was silence. The experiment was performed using 1,5 T MR system. Functional data analysis was performed using SPM2 software (Wellcome Department of Cognitive Neurology, Great Britain). In low proficiency group (LP) stronger activation was found in right inferior frontal gyrus (pars tiangulris) incuding insula and in the left hemisphere on the border of supramarginal and superior temporal gyrus. In high proficiency group (HP) more activated in second language (L2) was the left inferior frontal gyrus (pars tiangulris), and a small part of left middle frontal gyrus. Proficiency level of the second language influences the pattern of activation of language areas.