Анотация: For forest soils, which are naturally acidic, there is only a limited number of reports, concerning their cation exchange capacity (CEC) controlling mechanisms and on the possible impacts of acidic deposition, climate change and increasing harvesting pressure for biofuels. Therefore, the aim of this investigation was to characterise the cation exchange capacity of forest soils (Dystric and Eutric Cambisols) under beech stands (Fagus sylvatica L.) from the Central range of the Balkan mountain and from the Osogovo Mountain. The cationexchange properties have been analyzed following the methodology of Ganev and Arsova (1980)