The main goal of the following article is an answer to the question on the role of the legal institutions in the processes of the societal collective memories petrification. Through the comparison of the normative basis for the functioning of the institutes for the national remembrance, in Poland and Ukraine, my crucial intention is a presentation of the regional specificity of the state impact on the processes of collective co-remembering in the particular postcommunist societies in Central and Eastern Europe, with the references to the characteristic elements of the regional constitutionalism. Necessary to identify and to explain is the inevitable fundamental difference between states’ memory policies in the presented countries and their approach to the institutions. The text starts from the comparison of the institutes for the national remembrance, but my intention is to explain the differences trough the analyses of the legal and socio-legal background of their functioning.