The article is concerned with the study, classification and evaluation of the most popular trends in the development of modern architectural thought in the Irkutsk city. For more than 350 years of its history, Irkutsk has passed a difficult way from a fortress to a large trading city, and then to an industrial and scientific center of the Asian part of Russia. More than once, the coming times turned out to be completely opposed to the previous ones and in each of them the appearance of Irkutsk changed dramatically, moving into fundamentally new categories. Today the comprehensive scientific study is equally important for both the theoretical and practical aspects of architecture. A time-phased appeal to history will make it possible to analyze the advantages and disadvantages of such exceedingly diverse and distinctive contemporaneity, but only if we understand the general spatial environment process. Actualisations of the conclusions about its nature, in turn, will allow to judge competently the validity, rationality and perspectivity of the latest trends in design and construction for the region. Various periods of progress are considered in the context of such a phenomenon as the architectural identity of the city. The search for its meaning, possible expressive principles lead us to the conclusion about multipolarity, artfully placed contrasts as a distinctive feature of the image of the East Siberian capital. The key issue, to which this study is devoted, is to identify the priority ways to maintain, disclose and compositionally clarify the unique environment of the Irkutsk city.