The paper presents an analysis of different interpretations of the term imperium, a public and legal category characteristic of the supreme magisterial power in the Roman republic. The author considers Th. Mommsen's hypothesis of originally polyfunctional imperium, as well as HeuB' hy pothesis that imperium meant nothing but high military command. She also describes some variants of these concepts developed by their adepts in later times with special attention to the theory ofW.Kunkel. The achievements of modern Roman studies give the author grounds to confirm the idea of military sources of imperium. She does not, however, support the view that imperium retained its purely military denotation throughout the history of the Early and Classical Republic. She maintains that the polyfunctional character of imperium can be traced back to the cenruriate organization introduced by Servius Tullius, which fixed the unity of military and civil life in the community and of the relevant power functions. It may be deduced, the author goes on to say, that one cannot speak of a five centuries' long evolution of the concept of imperium in the sense of its expansion in the judicial and civic field. The author concludes that the power implied by imperium was always the same (irrelevant of whether the person endowed with it was an ordinary magistrate or an extraordinary one, whether his functions were military or civil or whether his official position was higher or lower). She describes the range of rights implied by imperium: 1) the right to communicate with gods on behalf of the community and to conduct auspicia; 2) the right to convoke the comitia and to introduce bills; 3) the right to convoke the senate, to introduce bills and to demand a resolution considering the proposal; 4) the right to take high military command; 5) the right to conclude a truce (but not to make peace) with the enemy; 6) the right to distribute the loot; 7) the right of the supreme administrative power; 8) the right of the supreme judicial power; 9) the right to appoint solemnly his successor to be invested with imperium; 10) the right to appoint the praefectus Urbi; 11) from the last third of the 4th с. ВС, the right to become a promagistratus after the expiry of his office; 12) the right to have the insignia. Special attention is paid to the supreme judicial power implied by imperium, in particular to the meaning of coercitio. In the author's opinion, the jurisdiction (iurisdictio) of Roman magistrates endowed with imperium included the right to summon the offender {ius vocationis), to arrest him (ius prensionis) and the right to appoint the punishment directly (ius coercitionis). The author comes to the conclusion that there could be different fields of exercising imperium, different conditions of it and different public and legal mechanisms of its realization. These mechanisms could either restrict the execution of the power implied by imperium or, on the contrary, facilitate its fullest possible realization. As examples of such mechanisms which could be provisionally suspended (in order to realize the full potential of the summum imperium) she mentions: the right of provocatio to the people, collegial intercession, the right to appeal to another magistrate, intercession of plebeian tribunes, hierarchy of the magistrates endowed with imperium and specialization (provincia). The author concludes that imperium of Roman magistrates was polyfunctional not only in Late Republic, but in Classical and Early Republic as well. The difference between the bearers of imperium consisted not in the extent of their power, but in the ways and methods of its realization.