The polysaccharide of peach gum, prepared by a partial acid hydrolysis, was degraded by a mixture of extracellular glacanohydrolases of Aspergillus flavus. This way obtained polysaccharide differed from the original one especially by a higher content of D-mannose and a lower content of D-galactose bound by (1 3) glycosidic bonds. The obtained results are discussed from the standpoint of composition of the main and side chains of the native polysaccharide.