The article deals with the prospects for the integration of two micromodels of political action — behaviour guided by the logic of rational choice and behaviour based on the logic of accordance with certain legal or moral principles — and with the possibilities of employing the resultant complex model for the creation of a consistent theory of institutional changes. As the basis of the synthesis sought for, it is proposed to use the principles elaborated within the framework of a new school of modern psychology — cultural-historical theory of activity — in combination with certain tenets of politico-administrative sciences. The article consists of 4 parts. In the 1st part, concepts of the cultural-historical theory of activity are considered, which are required for the describing of the phenomenon of political activity. In the 2nd, the role of the results of symbolic production in the maintenance of the formal institutions’ stability is discussed. In the 3d, specific character of politics as a form of human activity is investigated. The 4th part presents an outline model of institutional changes, with principles of the cultural-historical approach as its foundation.