Oxygen consumption and carbon dioxide production in some Arctic soils were measured in different thermic and humidity conditions. Testing temperatures was following: 4, 8 and 12°C. The rate of metabolic processes was temperature and humidity dependent. In the temperature of 4°C the metabolic processes intensity was negatively correlated with humidity, however in higher temperatures the higher was the humidity the higher was also the intensity of metabolic processes. The interaction of humidity and temperature is probably to great extent responsible for low rate of decomposition processes of organic matter in polar conditions.