Abstarct: A water-soluble polysaccharide was isolated from the roots of Rubus anatolicus by water extraction at 70 ͦ C and purified using chromatographic columns of Cellulose DEAE-52 and Sephadex G-100. The homogeneity and molecular weight of purified polysaccharide were determined by using HPGPC. The specific rotation, monosaccharide composition, methylation analysis, partial acid hydrolysis, periodate oxidation, Smith degradation, NMR and IR spectroscopy were used to determine polysaccharide structure. The results showed that the polysaccharide of R. anatolicus roots was an acidic heteropolysaccharide that has glucose, galactose and glucuronic acid in a molar ratio of 6.2: 1.0: 1.2, respectively, with a specific optical rotation of + 196◦ and an average molecular weight of 7900 Da. The main chain of the pure polysaccharide of R. anatolicus roots was composed of α-D-Glcp with α (1→4) lixnked and its side chains were made of α-D-Galp-(1→ and α-D-GlcpA-(1→ residues remains attached to the O-6 of glucosyls in the main chains.