Samples from forest and cultivated soils, from ruderals and alluvia, from the rhizosphere of the cover of pastures and from mosses and water algae were evaluated. Data represented 88 species, 52 genera, 33 families. In 50 g samples there were 13-516 specimens of nematodes with a biomass weight of 3.414-413.290 mu g, bound by the energy value of 0.1349-16.3346 J.