The number of soil mesofauna and enzymatic activity of soils are good indicators of changes in soil influenced by cultivation. The aim of this study was to compare density of enchytraeids and the activity of dehydrogenases (ADh), urease (AU), and invertase (AI) in the soils of grassland and arable land. Relationships that exist between those biological parameters and the basic soil properties (the content of total organic carbon (TOC) and nitrogen (TN), pH, texture, and total porosity) were defined. In the research, soil material from humus horizon of 12 soils which were located in the Mały Beskid and Silesian Foothills (S Poland) was used. The main density of enchytraeids in grassland soils (12 982 ind⋅m-2) was twice higher than in arable land soils (6099 ind⋅m-2), and the differences were statistically significant. Grassland soils were characterised by higher enzymatic activity than arable land soils. However, only ADh, which were almost three times higher in grassland than in arable soils (2024 and 742 μmol TPFkg-1h-1, respectively), showed significant differences. In grassland soils more favourable edaphic conditions for the development of soil organisms occurred in comparison with arable land.