The purpose of this paper is to record observations about the system of document storage in the monastery archive and the principles of systematization of ownership documentation used in the Kirillo-Belozersky monastery in the 15th — 17th centuries. Any large landowner, including ecclesiastical corporations, faced the need to systematize ownership documents related to different ownership complexes. Although it is sometimes possible to reconstruct the composition of owner archives or at least parts of them, the internal structure of family archives, methods of storage and systematization of documents in them, in most cases remain unknown. The owner archives of church institutions occupy an intermediate position between the huge state archives and the local archives of private individuals. Among them is the Kirillo-Belozersky Monastery, the second largest landowner among the ecclesiastical corporations of the Moscow state. By the beginning of the 17th century its archive included more than a thousand documents, and by the end of the century it had at least doubled. Such a large array of documents required the development of a storage system that would allow not only to solve the problem of their preservation, but also the possibility of searching for the necessary data. Comparing the sources that somehow describe the monastery fiefdom or the owner's archive (Description of the Archive of 1591, Descriptions of the monastery treasury in inventories of 1601, 1621, 1668, copy books of the late 15th and 17th centuries, the centurion book of 1544 and the census book of 1601), we see that the monastery documentation was compiled without reference to cadastres. There is also no linkage of the structure of the monastery archive and the order of archive funds to the state descriptions of the monastery fiefdom and the structure of intra-monastery documentation. Thus, the structure of the archive and the order of funds in it were formed directly by the archive staff on the basis of their own ideas. The staff of the archive of the Kirillo-Belozersky Monastery managed to effectively systematize the documents by separating into a separate fund the charters relating to the entire monastic fiefdom or its several parts. This made it possible to group the rest of the documents according to the geographical principle, separating the acts related to specific ownership complexes into separate fonds. Such a principle of organization of the archive and its structure was caused by practical needs and, as it seems, was the most optimal for the available corpus of acts of the Kirillo-Belozersky monastery.