The polysaccharide was extracted from G. lucidum mycelium by submerged fermentation after previous hybird optimization. The polysaccharide of G. lucidum mycelium was separated by DEAE Sepharose fast flow column. Then we used high volume exclusion chromatography (HPSEC) to explore purity of three polysaccharide fractions and complete acid hydrolysis and PMP pre column derivatization RP—HPLC to measure the monosaccharide composition of them. At last, multi angle light scattering instrument combined with device (SEC—MALLS) was used to measure the Mw of polysaccharide fractions, while the slope of curves between the molecular rotation radius and molecular molar of moles inferred the space conformation of them. HPSEC results showed that the purified of GLMP1, GLMP2 and GLMP3 were 93.58%, 97.64% and 99.19%. Monosaccharide composition analysis showed that mannose, rhamnose, galacturonic acid, glucose, galactose, xylose, arabinose and fucose were contained in GLMP1, GLMP2 and GLMP3, however they had different molar ratios of monosaccharide. SEC—MALLS tested the absolute weight-average molecular weights (Mw) of GLMP1, GLMP2 and GLMP3 respectively were 4.526×10⁵, 4.603×10⁴ and 3.760×10³ g/mol and it suggested that the conformations of the three polysaccharide fractions maybe were polymers which were high tightening and having branched structures.