In this research; details of the art history research methodology used by Sirarpie Der Nersessian, the historian of the Byzantine and Armenian art, in academic publications were identified and understood to be a three-stage method of technical, artistic and iconography. This finding was provided by Der Nersessian’s academic publications, which contain methods based on different academies. In this respect, Der Nersessian’s methodology of 13 articles, 3 bibliographies and 1 book publication explains how a comparative analysis of art history-specific scientific researches and a method developed at the limits of the formalist reviewer were developed. Selected publications have been handled chronologically in order to examine Der Nersessian’s systematic method and the sources that he used in his publications and the academies involved in the research method have been examined. By this study it has been understood that Byzantine, Armenian, Georgian, Turkish, Slavic, Arabic and Syriac arts dated to certain centuries intervals can be obtained definite judgments from the findings if they are examined separately from the disciplines of theology, history and linguistics by comparative method. In the conclusion section of the research; Sirarpie Der Nersessian’s three-stage research method has been extensively identified. In this context, it is stated that Bertay Gospel, Tetravangelia Paris 74, Etchmiyadzin Gospel, II.Basil Menologion, Nicodemus Gospel, Smpad Armenian Chronicles, Paris Gr.510, Barlaam and Joasaph’s novels are investigated with this method.