This paper presents the results of measurements of soil respiration in two beech associations on the mountains Stara Planina and Fruska Gora. The measurements were carried out from May to September on previously marked points in selected stands. In addition to soil respiration, at the same time measurements of evaporation, soil moisture content and air temperature were made. The results showed different values of soil respiration in relation to site results can be explained by differences in temperature regimes of measurement locations and the daily variation in the intensity of soil respiration.