Nowadays when the role of knowing of foreign languages is extremely high and the demand for specialists which are proficient in a language is increasing impetuously we face the problem of desire absence to learn foreign language among non-linguistic majors. We supposed that the type of teacher-student interaction style (the authoritarian, democratic and liberal) could influence the students' motivation type (internal, external positive, external negative or amotivation) and this was the aim of the study. 230 the second year students of the day department seeking a baccalaureate degree from Moscow State University of Food Production participated in the experiment. Among the respondents there were 143 girls and 87 boys aged 18-20, citizens of the Russian Federation. The experiment was divided into 3 stages and it took us 3 semesters to complete the study. The aim of the first stage was to investigate the students' preferences related to teaching style, educational teacher-student interaction style as well as the prevailing type of learning motivation to study in common and to learn foreign languages before the main part of the experiment. The second stage of the study was aimed to investigate the way how the educational teacher-student interaction style influences the nature and type of students' motivation to learn. At the last stage of the study, the output testing of student performance was implemented and all the results from the previous stage were compared and analyzed. The results of the experiment clearly demonstrate that both authoritarian and democratic teacher-student interaction style could give positive influence on students' educational behaviour and academic performances while the implementation of the liberal teacher-student interaction style leads to amotivation. At the same time, the democratic style, contrary to the authors' hypothesis, provoked, predominantly, not internal, but external motivation, while authoritarian styles significantly activated internal motivation.