The studies have been accomplished in two ecosystems with different microclimatic, vegetation and landscape features: Peresecina and Trebujeni areas. On rocky woody slopes of Trebujeni the insectivores, carnivorous mammals and chiropterans are characteristic (Wa > 5.0), in opposite to Codru forest near Peresecina village, where the anthropogenic influence is much higher and the mentioned mammal groups are accessorial. The rodents have in both stations a constant ecological significance, the population density reaching the maximum values in July. The dominant rodent species had rather high trappability index – between 28% and 32%. The common insectivore species (hedgehog and mole) are frequent and wide spread in both studied areas. The shrews (common and white toothed) are more frequent in Trebujeni area, due to the proximity of the Rut river. The carnivorous mammals have the density and the frequency much higher in Trebujeni area, due to more favorable shelter conditions, which they found in rocky slopes of the Rut banks. The artiodactyls (roes and deer) were rather rare, due to intense use of the studied forest ecosystems as recreational areas and forest management activities. The chiropteran density was also significantly higher in Trebujeni area, due to landscape peculiarities, which conditioned the existence of many caves, grottos and other formations suitable for bats prosperous existence. In both studied areas, a decrease of mammal community diversity was registered during summer period in forest ecosystems, as well as in adjacent agroecosystems. The analysis of similarity between various ecosystems revealed that the similarity index is higher for agrocoenosis, while the forest mammal communities are less similar.