A comparative study of the processes of accumulation and degradation of galaсtomannans of seeds of some species of the family Fabaceae Lindl. s.l. was carried out. Quantitative characteristics of galactomannan content and mannose : galactose ratio in a galactomannan molecule were determined during ripening and germination of seeds of the species of the genus Galega and Astragalus . The data ob-tained may serve as the basis for search of sources of galactomannans adapted to the con-ditions of the temperate latitudes.Key words: polysaccharides, seeds, legumes, galaсtomannans, ripening, germination.