The presentation will address how both, the european law and the Spanish Constitution have changed the legal sources in Spain. The first, by creating a complete new legal system that relates in many ways and binds the national legal systems of the member States of the EU; the second, by laying down the basis of an administrative state, subjected to a normative Constitution and the restraint of judicial review. Furthermore, she will underline how the addition of these elements have contributed to a severe transformation of the legal sources regarding administrative regulations and judicial precedents.