In the article, the author undertakes to consider in theoretical aspects the relationships between the post-Communist institutions with common Communist legacy, i.e. between the former Communist parties (successor parties), the trade unions and the state. In the general form, the successor parties, the trade unions and the state are presented as interrelated participants of post-Communist transformations. More particularly, two models of the relationships between the successor parties, the trade unions and the state have been distinguished in post-Communist Russia and in Central and Eastern Europe, and in order to illustrate the models, analysis of the cases of Russia, of Poland, and of Hungary has been carried out.