Determining the correct relationship between the sources of law existing during the communist period in Poland is today not only a historical asset. It turns out that the administrative courts conduct a lot of proceedings in which they are forced– while examining the legality of the decisions on expropriation from the 50’s of the twentieth century – to use the normative acts issued in the communist era. In this context, there arise problems related to identifying the impact of the provisions of the resolutions of the Council of Ministers on the interpretation of other pieces of legislation, particularly statutes and decrees. In this paper the author argues that the regulation on expropriation procedures in light of the provisions of the Constitution of the Polish People's Republic of 1952 fall within the scope of exclusivity of a statute. Courts adjudicating on matters of legality of decisions taken during the communist period cannot modify the significance of the act of a higher rank (statute, decree) based on the provisions of the resolutions of the Council of Ministers. It is one of the key directives of interpretation which must be used also to determine the content of legal acts issued under the Constitution of the Polish People's Republic.