The article examines the approaches that have been used by historians at source study of cadaster books since the “discovery” of these documents till modern science. This is a specific group of Russian written sources of the late Middle Ages. At every stage of historiography scholars gave a priority to specific aspects of cadastres studying. The development of “stereoscopic” view of the source should be the most important task of the present stage. In this paradigma the informative capabilities of each block of data are considered with regard to their origin, ways of penetration to the manuscript, methods of data collection and processing.