The author's purpose is to determine the role of professionally-political unions in the process of constructing the intelligentsia's collective identity in Siberia according to the principle of similarity of political views. To realize research intent the article cites unpublished documents of professional unions (resolutions of meetings, proclamations, policy documents) stored in funds of local and central archives. Materials of local periodicals as well as unpublished documents of judicial bodies and police have also been used as additional sources that helped reconstruct the event outline of the process being researched. An analysis of the position of the trade unions of the intelligentsia on topical issues on the political agenda of 1905 confirmed their consistency with the main directions of the Liberation Union's program, on whose initiative they were created. In discussing scenarios of liberal democratic development, the members of these unions have established themselves in the choice of their political preferences. However, this choice had been made earlier. It was determined by the pattern of thinking, moral principles, social settings of the Siberian intelligentsia representatives rather than the affiliation with the Liberation Union. Professional political unions established let them realize the need for consolidation that intensified sharply under the conditions of transformation of the habitual way of life according to the principle of common political views. Communication with "the significant others" that was being built during outreach activities of the members of the unions, as well as in contacts with public organizations different in their social composition and political attitudes who allied themselves in the Union of Unions was an important factor in the formation of collective identity of the initiative minority. In general, the analysis of the process of ideological and political self-identification of the Siberian intelligentsia made it possible to reveal in many ways situational nature of collective identity, the institutional embodiment of which was the professional unions. The mobile nature of the identity formed on the basis of the similarity of political views and attitudes caused the short-term existence of these organizations. Having fulfilled their role as an organizational form of political self-determination of the intelligentsia, they had already lost their significance by the beginning of 1906 and had given up their place in the social movement to political parties.
