Kefiran is a water-soluble polysaccharide extracted from kefir grains biomass. The identification and quantification of kefiran monosaccharides were carried out by HPTLC after the complete acid hydrolysis of kefiran solutions. The mobile phase was a mixture of n-propanol: acetic acid: water (70:20:10, v/v). For derivatization was used p-aminobenzoic acid and o-phosphoric acid in methanol. The identified HPTLC fractions were glucose (Rf 0.71) and galactose (Rf 0.66), which indicates a high purity of the extracted kefiran. The relative concentrations of each monosaccharide identified in samples are dependent on the initial molecular weight of the polymer chain. The kefiran isolated from kefir grains grown in milk is a heteropolysaccharide which contains D-glucose and D-galactose units in a ratio of 0.94:1.1.