The study analyses the potential effects of the Treaty on the Hungarian Constitution and its application by the Hungarian Constitutional Court, and the more general-and at the European Law’s present stage of the development unavoidable-problem of the theoretical analysis of European Law as a branch of law.The study points out that the Hungarian Constitution’s Accession Clause (Article 2/A) has not solved the problem of the primacy of Community Law, as far as the relationship between EU Law and the Hungarian Constitution is concerned, therefore the Constitutional Court encounters a problem that is increasingly difficult to resolve, when facing issues relating to the incompatibility of Hungarian statutes with EU Law. The study criticises some solutions proposed by the Constitutional Treaty (e.g. the institution of “recommendations”-(the present practice of “guidelines” etc.) which is definitely unconstitutional according to the Hungarian Constitution and its application practice by the Constitutional Court. Finally the study complements the problems thus outlined with the fact that the concept of EU Law and its various parts have not been clarified from a dogmatic perspective-the time has come to systematize this enormous material of law, especially when a Constitutional Treaty makes the attempt to summarize the legal fundaments of the unprecedented effort to develop an economic and political integration in Europe.