The emergence of features of Armenian Christianity, the transformation of the Armenian Church in Ukrainian lands is an interesting and unexplored topic in Ukraine that is closely related to the unresolved and nowadays problems of split Christianity and the emergence of different currents in it. Turning to the historiographical analysis of the sources devoted to this problem, the researcher of the Armenian Church is faced with the need to take a new approach to the study of this phenomenon, to evaluate in a modern way the fact of the appearance of monophysitism. This is due to the fact that the vast majority of works on the Armenian Church are of a partial and, for the most part, historical nature, and also have a significant confessional color. First of all, we are talking about the criteria for analyzing and defining the research framework. A characteristic feature of the available sources is the avoidance of the Chalcedon problem and, accordingly, questions about the essence of monophysitism, which a priori recognize heresy. The conceptual basis of these works is certain postulates, on the basis of which the system of analysis is built, namely: to the V century. there was a single catholic Christian Church from which various schisms and heresies began to break away from various non-Orthodox, non-Catholic, erroneous movements and organizations; the decisions of the Ecumenical Councils are true in the last instance and the documents approved by them are not subject to discussion.