The article presents the results of a study of natural radionuclides (226Ra, 232Th and 40K) content in the soils of the Severny Island of the Novaya Zemlya archipelago that were sampled prior to the first nuclear tests. The humus content in the soils varies from 1.4 to 6.5%. Soil pH levels vary from moderately acidic (4.7) to neutral (6.5). Fine soils are characterized by a light particle size distribution with a predominance of 0.25-0.05 mm and 0.05-0.0.1 mm fractions. The total volume of these fractions reaches 81-94%, which indicates the predominance of primary minerals and a low content of secondary (basic sorbents of natural radionuclides) minerals in soil. The content of radionuclides in soils is as follows: 226Ra: 11.9 5.1 (5.7-19.8) Bq/kg; 232Th: 13.6 7.4 (3.0-19.1) Bq/kg; 40K: 302 100 (224-493) Bq/kg. No Caesium-137 has been observed in the analyzed soils.