The Treaty establishing Constitution for Europe was signed in 2004. The former president of the V French Republic Valery Giscard d’Estaing was responsible for preparing this document. Constitutional Treaty replaced the previous treaties in one text. Considering the importance of the Constitutional Treaty, many countries decided to organize referendum for its ratification. President of France Jacques Chirac decided to organize referendum concerning this issue, too. Unexpectedly, Constitution for Europe was rejected by French people. The aim of this paper is to show the main reasons why the document was rejected by France – a country being not only a member founder of the EU, but also a ‘motor’ of European integration.