The focus of this article are paleoanthropological materials of the Russian first settlers in the Eastern Siberia that are not that numerous in today's studies as well as craniometrical data that is barely missing. All that determines the value of Irkutsk craniologic series of XVIII–XIX centuries. The purpose of the study is to identify ways to create anthropological structure of Irkutsk. Main tasks are to get the craniological characteristic of the Irkutsk residents compare the existing data to the available materials of the population in central and northern regions of Russia. Authors studied the cranological series of the first half of XVIII from the territory of the Irkutsk fortress – Savior necropolis (N = 82) and series of the Holy Cross necropolis of the second half XVIII – beginning of XIX centuries. (N = 44). Comparative material extracted from literature data of nine craniological series XIV–XVII and XIX centuries from excavations and medical documents of Moscow, Yaroslavl, Novgorod, Vologda, Pskov, Kostroma and Arkhangelsk region. The material studied by the standard craniometrical program. To assess the significance of differences it was applied the Student's t-test. The results of the studies revealed changes of physical appearances both men and women in Irkutsk in XVIII–XIX centuries. The distribution of significant differences suggests the transformation of the Irkutsk people was due to new immigrants, primarily from the central regions of Russia and the Russian North (Vologda).