The article opens up a new research series entitled “Significance of the Folklore Materials, stored in the Department of Manuscripts at IWL RAS and in other archives, both in Russia and abroad” and offers philological interpretation of the samples of Russian folklore culture, hitherto unknown to the broad academic community. These samples belong to the tradition fundamental for the development of Russian civilization and the meanings of national mentality. Folk culture / folklore play important role in this development, as do folklore studies that examine folklore sources, their ideological constants and aesthetics concepts. The study, focusing on the analysis of the newly acquired folklore heritage, attempts to evaluate the significance of these materials and ensure their harmonious entry into the already existing folklore system. The presented research will undoubtedly enrich both Russian folklore studies and literary criticism.