The master work presents the research of macrofauna (Lumbricidae) quantity, depending on the spieces of the plants grown and the hydrotermic modes. Research object: the soil macrofauna in the light granulometre composition of soils (in Akemnė district, Smiltinė village). Research objective: by field research to evaluate quantity of macrofauna (Lumbricidae) in the nothern part of Lithuania in the light granulometre composition of soils, in the ecological production farm, depending on the spieces of the plants grown and the hydrotermic modes. Research methods: the quantity of earthworms was established by digging 0.5 x 0.5 m and 0.25 m depth monolyths of soil, gathering earthworms, calculating, weitghting and measuring them. The research established that the quantity, weight, length of the earthworms depended on the species of plants grown, forecrops and hydrotermic modes. The most advantageous crops were the kitchen-garden, the garden, the potatoes. The best forecrops were the kitchen-garden. During the years of research strong reverse correlation links between the quantity of earthworms and the hydrotermic modes were established.