The geothermal information on the Siberian Platform in comparison with the data of kimberlite magmatism and deep platform structure were examined. On average the Siberian Platform does not differ much from the other ancient platforms of the world: its mean heat flow value is 38 - 40 mW/m2, mean temperature at the Moho discontinuity - 300-350 degrees-C and the thickness of thermal lithosphere - about 180-200 km. The highest heat flow - 50-70 mW/m2 - is observed within the Mesozoic depressions (Vilyuy, Kureyka, and Tunguska synclines) and of southern part of the Siberian Platform, occupied the Irkutsk Amphitheater and the Aldan Shield. The heat flow increase in these regions is related to last Meso-Cenozoic tectonic activity. The most interesting discovery is the low heat flow anomaly (about 20-25 mW/m2) in eastern part of the Siberian Platform, where the Yakutian kimberlite province is located. The lowest temperatures (about 80 degrees-C at the depth of 5 km) and the greatest thickness of permafrost (here and there more 1 km) are typical of this province. To explain this heat flow anomaly analysis of geothermal data and PT-values, as dedicated by geothermobarometry of xenoliths from the Udachnaya kimberlite pipe was carried out. It is shown that the average temperature of the Siberian Platform lithosphere has remained stable over last 300-400 Ma at least from the Late Paleozoic. Thick lithosphere (about 180-200 km) must also have existed during this period serving as "anchor" braking the movement of the Asian Lithosphere Plate. Joint analysis of different geothermal data leads the conclusion that the extensive low heat flow anomaly in the eastern part of the Siberian Platform is stationary and is younger then Yakutian kimberlite province. It is possible that the anomaly is caused by the cooling of the Earth's interior as a result of some kind of the explain processes may be genetically connected with the kimberlite magmatism.
