In this paper are presented the results of evaluation soil quality of forest ecosystems in Republic of Moldova, included in the systematic transnational grid of 16 x 16 km of European forest monitoring. These results are based on 40 samples of 10 experimental surfaces to fi xed depths of 0-10, 10-20, 20-30, 30-40 cm. Soil quality indices (pHl, humus, Ntotal, P2O5, K2O) were monitored according to harmonized and recommended methodology by the International program ICP-Forests.The values of analysis parameter refl ects the general particularities of soil types and are sometimes quite obviously infl uenced by biotic and abiotic factors (physical-geographical position, elevation, substrate, vegetation type, dominant species, etc.). The basis of their nutrient supply and the soil reaction of forest ecosystems observe that forest ecosystems dominated by oak species are subject to greater risk of threat to forest ecosystems dominated by ash.