Abstract: To Study the molecular weight and monosaccharide composition in polysaccharide from PBL1,PBL2 and PBL3.The molecular weight and monosaccharide composition in polysaccharide were determined by GPC-MALS-RI and HPLC.The results showed that the average molecular weight (Mw) of PBL1-1,PBL2 and PBL3 were 3.642×10³,1.206×10⁴ and 3.992×10⁵ g/mol,respectively.PBL1-1 consisted of D-Man,D-Glu and D-Gal with the mole ratio of 1∶0.34∶0.036.PBL2 was composed of D-Man,Rha,D-Gal UA,D-Glu,D-Gal and Ara with the mole ratio of 1∶0.29∶0.78∶21.89∶2.69∶0.63.PBL3 was composed of D-Man,Rha,D-Glu UA,D-Gal UA,D-Glu,D-Gal and Ara with the mole ratio of 1∶2.63∶0.47∶1.63∶0.83∶6.92∶1.34.The polysaccharide of PBL1,PBL2 and PBL3 from Lycoris aurea consisted of D-Man,D-Glu and D-Gal,which had considerable differences in molecular weight.

Key words: Lycoris aurea, polysaccharide, molecular weight, monosaccharide composition