The topic of this contributing text is the definition of constitution in recent domestic legal thought. There have been compared constitution defining notions by S. Vračar, L. Basta, K. Čavoški and R. Marković. The critical analysis revealed not only similarities and differences in the approach and results of the writer of this text, but advantages and disadvantages of the approach and results as well. S. Vracar sees constitution as a normative fixation of fundamental structural and functional elements of the state and legal system as regulators of crucial social processes and relationships between members of the basic community. According to L. Basta, constitution is an act of positivation (?) of the principles of procedural legitimacy. For K. Čavoški, constitution is a guaranty of liberty. According to R. Marković, constitution is the main law on national government by which individual rights and liberties are guaranteed. The concept of constitution given by S. Vračar is larger in scope, but smaller in contents, while those given by L. Basta, K. Čavoški and R. Marković are smaller in scope, but richer in contents, and, which is even more important, their concepts of constitution imply modern constitution, which is, in fact, novel in the history of law and the only legal constitution.