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 × 10~3,1.206 × 10~4 and 3. 992 × 10~5 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 wit...