This article studies the use of relief ornamental frieze of intertwining polyhedrons in the decoration of dome drums of Armenian churches of the initial period of the Zakarid era. Following the liberation of the country from the Muslim yoke, in the Eastern Armenia regions and Ani, construction activity grew rapidly, especially in church building. New monuments were erected in the spirit of the national tradition, which is especially evident in the plastic decoration of the exterior of drums. The author tries to build a chronological sequence of the use of the ornament in the friezes of the domes of Armenian churches, which leads to the conclusion that ornamental friezes of hexagons and octagons were primarily used in Ani monuments. The author notes the simultaneous popularity of these patterns in the architecture of the neighbouring state of the Anatolian Seljuks, whose cultural activity in its formation is closely connected with the Armenian one. The author sees the possible origins of the ornamental frieze with a polygonal structure in the drums of Armenian churches in the brickwork architecture of the minarets of Iran and Central Asia from the eleventh and twelfth centuries. In summary, the author emphasizes the existence of the tradition of decorating drums with a blind arcade topped with a decorative frieze in Armenian architecture long before the era in question, referring to the Cathedral of Ani which played an important role in the formation of the image of domes of the Armenian churches of the Zakarid era.