The article contains substantiation of the necessity of methodological complementarity in the research of political institutions’ dynamics. The author regards as methodologically promising the study of the impact the political institutionalization process receives from symbolic structures (symbolic moulds and codes) which determine the character of formal political institutions’ functioning. Particular role is disclosed in the article, of those symbolic codes of political legitimization, on which the trend and efficiency of institutional changes depend. In its turn, unraveling the cognitive-estimative schemes of political legitimization codes presupposes resort to the methodological strategy of concept-analysis, which allows, the author notes, to operationally represent, by constructing a verbal-symbolic vocabulary, the logic of institutional dynamics.