This article analyzes and highlights the particularities of the legal order of the European Union, which is characterized by the immediate, direct and priority applicability of the rules of European law in the internal legal order of the Member States. Thus, it is mentioned that the autonomy of the legal order of the European Union does not exclude the collaboration with national legal systems, which is expressed mainly by a participation of state authorities in the implementation of European Union law, which is carried out according to new rules, different from the classical ways of applying public international law. In conclusion, it is found that the study of the particularities of the legal order of the European Union is important from the perspective of the current interest of the Republic of Moldova as an associated state, but also as a potential member of the European Union in the future. In this regard, we must understand that the correct application of the rules of European law is an essential condition for achieving the goal of European integration provided for in the founding Treaties.