Abstract:Polysaccharides of loquat leaf was extracted and purified， and its composition was studied. The total soluble polysaccharide of loquat leaf was prepared from the crude extract which was primary purified by macrop－ orous resin and then precipitated by adding alcohol. Pure polysaccharides were obtained by DEAE-52 cellulose column chromatography and Sephadex G-200 gel column chromatography， and then the molecular weights of polysaccharides were determined by Sephadex G-200 gel column chromatography. The polysaccharides were hydrolyzed， and then the monosaccharide component and ratio were identified by thin layer chromatograph. Three fractions were obtained by DEAE-52 column chromatography， and then three components were obtained through Sephadex G-200 column chromatography that confirmed to be single component based on single sym－ metrical pea of the elution curves respectively， named PSL-1， PSL-2 and PSL-3. The molecular weight of PSL-1， PSL-2 and PSL-3 were 700，500，400 kDa respectively. The monosaccharide component and ratio of the three polysaccharides of loquat leaf were identified by thin layer chromatograph. PSL-1 contains rhamnose and glucose， and the ratio was 1 ∶ 0.602. PSL-2 contains glucose， galactose and rhamnose， and their ratio was 1 ∶ 1.415 ∶ 1.408. PSL-3 contains galactose and rhamnose， and their ratio was 1 ∶ 1.03.