In the present work a comparison was made of microflora abundance and activity of two enzymes in earthworm casts and in hydrogenous soil. The studies were conducted on variously mucked sedge-moss and alder peat at Kuwasy in the Biebrza river valley. Biomass of eathworms ranged from 42.7 to 119.7 g/m² season, whereas production of casts varied from 38 to 107 t/ha/season. Abundance of fungi in earthworm casts was 2-6 times greater than in mucked soil. Also greater development of cellulolytical microorganism and a higher activity of urease was recorded. On all the examined meadows there was noted a smaller (by ca 10-76 %) abundance of actinomycetes in casts than in soil.