The aim of my article is to present an overview of certain stages of Costantino Mortati’s scientific work (Constitutional Court’s judge and professor of law) on the basis of Italian bibliography. His most popular work, entitled “the Constitution in material sense” (1940) conforms to problems and methodology of Italian constitutional law, while it reflects to contemporary schools of European jurisprudence and changes of institutions and theories of modern state. Behind Mortati’s theories about the State and the Constitution, the Italian liberal state regarded as heritage of risor- gimento, and the symptoms of its crises, birth and fall of the totalitarian state and the fundamental public law-aspects of the democratic and republic state can be found.