The main goal of investigation is the analysis of ecological and geographical variability of morphological characters of alpine sculpin Cottus poecilopus complex in the Siberian rivers - Lena, Ob, Amur for identification of their taxonomic status. The data obtained have shown absence of taxonomically significant differences in phenotypes of fishes in the Amur and Lena populations. The sculpin from Altai reservoirs occupies geographically and phenotypically intermediate position between the European and East Siberian population groups. It allows making conclusion about subspecies level of its differences from those and others. The analysis of the literary data on molecular phylogeography and characters variability is testify to high intergradations level of allopatric populations and belonging to the same one species. It is possible to conclude that three population groupings from the Asian part of a general inhabiting area correspond to subspecies rank: C. p. altaicus Kaschenko, 1899, C. p. szanaga Dybowsky, 1869 and C. volki (Taranetz, 1933), and their taxonomic status is overestimated. Rank of populations of Tura River (Ob R. basin), Podkamennaya Tunguska (Yenisei R. basin), and also the rivers of the northern part of Russian Far East demands additional specification.