During the period 19992001, the microclimatic conditions (temperature and snow relationships) were studied in three localities of the Giant Mts. arctic-alpine tundra (Jestřábí boudy, Studniční hora, Modré sedlo). The studies focused mainly on comparison of the microclimatic character and the intensity of the frost processes (e.g. regelation) within dwarf pine polycormon (Pinus mugo) and in the open tundra communities (that means without the influence of dwarf pine). The air temperatures 5 cm above the ground (surface temperatures) and in the soil (5 and 10 cm below the ground surface) measured in the open tundra are lower than in the polycormons during the period with the snow cover; results were opposite during period without the snow cover. According to the evaluation of the surface temperatures the regelation is by 30100 % more frequent in the open area than within the polycormon. In the case of favourable meteorological conditions the relegation in the open tundra can proceed in any season without the snow cover (the highest frequency of the regelation occurrence is in spring and autumn months, namely April June and September October). The studies in the Modré sedlo locality revealed that dwarf pine can completely eliminate the frost processes in soil on some places of vegetated-cryogenic zone of the Giant Mts. tundra.