The Atlantic Forest is a conservation hotspot due to its elevated level of biodiversity and current state of degradation. Some areas of Atlantic Forest have been replaced by eucalyptus monocultures in Brazil. Soil arthropods can be important indicators for assessing the recomposition of native forests after disturbs. This study aimed to test the hypothesis that exist differences in the composition and structure of soil arthropod communities among two plantations of eucalyptus (Corymbia citriodora) in different stages of natural regeneration of Atlantic forest (YP = Young Plantation and MP = Mature Plantation, in less and more advanced stage of regeneration, respectively) and a fragment of Atlantic forest (FOREST), in wet and dry seasons, in União Biological Reserve, Brazil, using pitfalls. Archaeognatha, Diplura, Opilionida, and Thysanura were restricted to the FOREST, while Diptera, Isoptera, and Orthoptera were favored by the microclimatic conditions in eucalyptus plantations. Soil arthropod community in FOREST was more complex than those in eucalyptus plantations. In general, soil arthropod communities showed higher total abundance and richness of groups, while equability decreased, as regeneration of Atlantic forest advanced in eucalyptus plantations, making this community more similar to that observed in the FOREST. The average total abundance, average richness, and total richness of soil arthropods were higher in the wet season in all areas, but the opposite occurred for the equability. Soil arthropod community improved with the regeneration of native forest species under the eucalyptus plantations.