Based on paleotemperature modeling, evaluation of Neo-Pleistocene permafrost rock thickness impact on geothermal regime of the petromaternal Togur deposits has been performed within the territory of oil fields of the Tomsk region (the southeast of Western Siberia). It has been stated that paleopermafrost with the thickness of about 300 m must be considered for appropriate reconstruction of geothermal history of petromaternal rocks in the south-east areas of West Siberia. This condition is relevant to a consistent consideration of thermal history of maternal deposits in course of assessment of resources by a volumetric- genetic method.