Surface snow samples from the inland high plateau, East Queen Maud Land, Antarctica, show unique chemical characteristics. They are characterized by high acidity accompanying the high electrical conductivity, so that the hydrogen ion is the dominant ion, coupling with chloride and nitrate ions. The chemical composition differs sharply from sea salts. These characteristics appear more clearly than previously reported in Antarctica and are most strongly developed in snow samples from the high region. The tritium content increases in the inland high area, especially in the region higher than 3600 m asl (above sea level), which corresponds to the region where the effects of katabatic wind have vanished in the glaciological observations. The highest tritium content occurs in the vertical profile at a snow pit (3761 m asl, 77¿00' s, 35¿00' E), which corresponds to the snow deposition in 1966. The concentration is the highest ever reported in Antarctica and is almost as high as the one observed in the precipitation in the inland region of North America, which is the highest value ever reported in the world. All the results suggest that most of the ions contained in snow samples from the inland high plateau, especially higher than 3600 m asl, are not brought directly through the troposphere from the sea around Antarctica but from the higher atmosphere and that they are under the influence of the physicochemical reactions occurring there. ¿ American Geophysical Union 1989