Algae were studied in the eutrophic peat bog (Plesetsk Region, Arkhangelsk Oblast). One hundred sixteen species represented by 120 specific and intraspecific algal taxa were identified. The division Chlorophyta prevailed. Spectra of life forms, ecological groups and morphotypes of algae were determined. Both typically edaphophilous and hydrophilous species (history of the biotope) take part in formation of soil flora of the bog.Key words: soil algae, eutrophic peat bog, Arkhangelsk Oblast.