In this article the essence and staples of the rhetorical culture of prominent national scientific IvanAndriyovychZyazyun are found out onthe basis of analysis of the publications sanctified to the research of his activity as a scientist and a teacher,the videos of his performances on different measures.The historical and biographicalanalysis of I. Zyazyun’s creative activity gave an opportunity to educethe key factors that had influence on his becoming as teacher-speaker. Among them the author distinguishes innate artistic capabilities, stage- creative and teaching activity, influence of teachers-tutors (school teachers and teachers of T. Shevchenko Kyiv university), works of prominent teachers-masters (A. Makarenko, V. Sukhomlynskyi), representatives of the dramatic art (K. Stanislavskyi) and the oratorical art (D. Carnegie).I. Zyazyun’s lecturer activity is considered in the article. The prominent teacher activated the work of idea, constantly supported the attention of the audience through the rhetorical facilities to bring over students to active co-operation. It was promoted by the reasoning aloud, the dialogue expositions, the ability to conduct conversation naturally, to convince, to suggest. The teacher-speaker owned the technique of speech (clearness of pronunciation, rich intonation palette, pleasant (light) timbre, possession voice and professional breathing, etc.). This major aspect of the rhetorical culture was a result of the systematic workwiththe development of vocal vehicle (using the accomplishments of theatrical pedagogics, actor training, methods and receptions of K. Stanislavskyi’s system), and also huge experience of teaching activity, performances on conferences, participating in different measures. The influentialness of academic speech also increased with the use of unverbal facilities of communication, unique manner of the performance. The oratorical receptions that were used by I. Zyazyunin the process of reading of lectures are educed.In the article the main constituents of rhetorical culture of the prominent master of pedagogical word are determined. They areintelligence, validity, terminological exactness, simplicity, availability of exposition, tolerant, truly humanistic attitude toward interlocutors, clearness of pronunciation, expressiveness, emotionality, intonation riches and flexibility, pleasant characteristic timbre of voice, artistry, clear structure of oratorical performance, demonstration of own vision of problem and ways of her decision, use of receptions of bringing in and withholding attention audience (unusual beginning, rhetorical questions, the use of logical and psychological pauses, dialogue speech is appropriate, reflections aloud, etc.), rhetorical path and figure (metaphors, hyperbolae, epithets, rhetorical comparisons, rhetorical questions), authorial neologism, aphoristic character expression.Thus, the author comes to the conclusion, that I. Zyazyunis the "elite speech personality", prominent representative of national academic eloquence, who owned the highly developed rhetorical culture.