The author raises the question whether the term «military clientele» may be applied to the complex of relations between the emperor and the army during the period of Principate. Modern scholarship does not give a uniform answer to this question. Some scholars put a special stress on the personal character of relations between military leaders and the army in the late republi-can and early imperial periods and think it possible to speak about mutual duties of patronate-and-clientele type as one of the main factors of the transition from republican rule to principate. Other researchers either use the term of military clientele very cautiously or avoid it when de-scribing relations between the princeps and the army, or else consider that these phenomena had no special military specifics and must be classed among usual patronate-and-clientele relations. The author of the paper maintains that patronate-and-clientele relations (very much charac-teristic of the Roman society in different periods of its development) constituted an important aspect of the relations between the emperor and the army; secured by the military oath and cus-tom they were based upon a kind of contract. Personal character of late republican and early principate armies was very well realized by the contemporaries. Monopolization of the military clientele on the part of principes was one of the key factors in achieving political stability. After the establishment of the principate military service came to be regarded as a service rendered personally to the emperor and the army as belonging to him personally not just because of his position as commander-in-chief, but also because of personal duties and relations. The military clientele included various specific informal components (the idea of emperor as a the only source and distributor of marks of distinction and material benefits, strong dynastic feelings among the soldiers, identification of military duties with personal faithfulness to the emperor and his family). Together with ideal, symbolic and legal factors, of great importance was the way the emperor fulfilled his material duties and met the soldier's everyday needs. Military cli-entele was specific because of the fact that the army, especially the detachments consisting of citizens, i.e. legionaries and praetorians, acted as one of the contracting sides, which (unlike the city plebs) would take up serious responsibilities and preserved a sort of civic consciousness, thus being able to insist on fulfilment of the patron's duties if this became necessary. This sys-tem of relations implied that the military men, remaining adepts of monarchy, could think of themselves not as of subjects, but as of partners and warranty of the emperor's power. The spe-cific character of military clientele was to a great extent determined by the ethnic parameters. Describing the relations between the emperor and the army as a kind of clientele makes it possi-ble to define more precisely (than the term of hired army) that specific position which military forces held in the political structure of the imperial Rome. The material analyzed in the article shows that the system of relations between the army and the emperor, like other legal, social and political structures of the Empire, absorbed both the old Roman republican traditions and their «mutations» and the innovations that appeared during the crisis of the republic, which, having undergone in their turn some transformations, determined the double (republican and imperial) nature of the Principate.