The article deals with the problem of the creation and existence of the manuscript heritage of archbishop Feodosii (1491-1563), who was the head of the Novgorodian diocese from 1542 until 1551. It was noted that the epistolary heritage of Feodosiy is one of the most numerous and diverse among the works of the Novgorodian archbishops of 16th century. 30 texts written by Feodosii which are preserved in 15 manuscript collections in the stacks of St Petersburg and Moscow were analyzed. The main attention is paid to collections of RNB. Q.XVII.50, GIM. Eparch. Number 416, GIM. Shuk. Number 465 and BAN. 16.17.29, containing a core set of texts that belong to Feodosii. The differences of two collections identified in the course of the analysis are shown. While Evfimievskii collection (RNB.Q.XVII.50) contains the extended versions of the texts of Feodosii, Formulary (GIM. Shuk.468, BAN. 16.17.29) includes their brief editions. The process of the collections’ formation was demonstrated and the comparative analysis of Feodosii’s texts was performed. The article presents the reader the systematization of Feodosii’s archive by the time and place of writing, recipients and subjects. The author outlined the persons involved in the correspondence with Feodosii, including members of the clergy and people of the diocese of Novgorod, Ivan IV, Metropolitan Macarius and others. It is noted that Feodosii skillfully applied in his messages literary methods relevant to the 16th century. For each of the addressees Feodosii finds special words, according to each case. It was noted that Feodosii paid attention to the issues of national importance, such as the war with Kazan. The article also addresses the question of the Feodosii’s attitude to the Moscow leadership, which is manifested in the text of his messages.