Abstract: Modern approach to the study and preservation of archaeological sites is based on the complex application of natural-science and archaeological methods. The development of archeological site study algorithm (aerial photography, geophysics, soil examinations, etc.) is a topical research trend. An effective tool to compare different data is a geographic information system which contains not only traditional cartographical and thematic layers, but also transformed maps (which result from the application of operators to initial maps) and interpretation layers (which result from the comparative analysis of the transformed maps). The article addresses the Kushmanskoe settlement dated 9th-13th centuries AD. It was one of medieval Finno-Ugrian settlements in the basin of Cheptsa river (the northern part of the Udmurt Republic). To interpret the interdisciplinary data complex the author offers informative markers to estimate the preservation state of the cultural layer and decision rules to recognize the areas with characteristic properties. As a result, the author has determined the boarders of the settlement parts with different preservation state of the cultural layer: that with transformed surface and a substituted one. He has also found a part of “household periphery” Uchkakara – a boarder of the cultural heritage object. The analysis of mutual alignment of geophysical anomalies related to local underground objects let the author reconstruct proper layout of the settlement.