Relevance of study. Symphonic creativity of a representative of the Kyiv Composer School, Honored Artist of Ukraine, I. Ogienko, A. Vedel, I. Nechuy-Levitsky prizes winner, winner of national and international composer competitions of Olexandr Yakovchuk (born 1952) has been presented by eight symphonies, two symphonic poems, ten instrumental concerts. Such a quantitatively significant work reflects the peculiar artistic world of the artist, who is characterized by the spirit of intellectualism, philosophical approach in the understanding of historical events, the relief of lyrical expression, bright mastery of the method of symphony and the possibilities generated by it, orchestration. Covering both the early and the mature period of the artist's creative work, his symphonic style evolved, displaying at the same time certain stable moments related, for example, to the special attitude to the role of a group of brass instruments. Therefore, the problem of dynamics of A. Jacobchuk`s symphonic style (genesis, functioning, development, interaction with other artistic styles in the cultural context) is seen as a promising vector in the study of his artistic achievements, which occupies a prominent place among Ukrainian symphonic creativity (L. Kolodub, B. Bujevsky, Ye. Stankovych, V. Sylvestrov and others).Main objectives of the study are to reveal the peculiarities of A. Jacobchuk 's symphonies in the aspect of the problem of dynamics of formation his author style.The methodology of the research is based on the application of the cultural approach, source study, textual methods, as well as methods of holistic analysis and interviewing.Results and conclusions. The conflict-dramatic type of symphonism, that continues the tradition in Ukrainian music initiated by B. Lyatoshynsky, is predominant for A. Jacobchuk's symphonic music. From the early to the mature period of his creativity, his symphony style in its dynamics is attributed to non-canonical types of this genre. This is noticeable in the approach to cyclicity (two-part, one-part, six-part, one-part, enclosed in diptych), the advantage of programmability, samples of mixed genre with oratorio, requiem, concert. The national component of the style is identified mainly at the level of design, while in the vocabulary of music the examples of the use of characteristic intonation are isolated, but they carry a considerable semantic load in the concept. The leading role of brass instruments in the characterization of the main images, the culminating and summarizing zones of the form should be considered a feature of orchestral thinking