This study aims to determine the diversity and community structure of microarthropods in habitats dominated by different tree species. For this purpose, the microarthropod contents of the soil and litter samples collected in May 2017 from habitats dominated by the Arnold/Black pine (Pinus nigra (Arnold)), Oriental beech (Fagus orientalis (Lipsky.)) and Uludag fir (Abies nordmanniana (Stev.) subsp. bornmulleriana (Maid)) tree species were investigated. Soil and litter samples were collected from Arac, Karabuk and Safranbolu forests for Black Pine, Oriental Beech and Fir, respectively. Litter samples used in the extraction of microarthropods were collected using a cylinder of 5 cm diameter and were as thick as the litter cover, while 5 cm thick soil samples were collected from the upper mineral soil to a depth of 5 cm. Moreover, extra samples were collected from the same locations to determine certain physical properties of the litter and soil in those locations. Microarthropods were extracted from the litter and soil samples using the Berlese funnel method and were counted and classified using a microscope. According to the analyses, there were 74 different taxa throughout the three different ecosystems, and there was no statistically significant difference in terms of biological diversity. Based on tree species, the Fir forest had the highest average taxonomic richness (26 taxa), while the Pine forest had the lowest tree species-based taxonomic richness (19 taxa). Similarly, the Shannon's diversity index (H') was the highest in the Fir forest (2.65), while it was the lowest in the Pine forest (2.34). In addition, the litter layer (H' = 2.64) had a significantly higher biological diversity than that in the soil (H' = 2.39). The study is still in progress and any seasonal changes in the relationships will also be revealed with new samples collected during other seasons.