Polysaccharide was extracted by boiling water reflux method from the fruiting body of Ganoderma lucidum. Additionally, the purified polysaccharide was obtained by removing protein with Sevage way, ethanol precipitation, centrifugation, run water dialysis, membrane separation, concentration and frozen-drying. The structural characteristics, chain conformation and triple-helix conformation of ganoderma lucidum polysaccharide (GLP) were distinguished by Smith degradation, methylation analysis, and the wavelength change of the red shift of the mixture of polysaccharide and Congo red in alkaline solution, as well as IR, GC-MS, NMR, and visible spectrometry. The results indicated that GLP was a linear (1→3) β-D-Glcp main chain linkage. Its monosaccharide component was predominantly composed of D-Glc, and small amount of galactose, mannose, xylose and idose, residues of branches terminated with substituted at 1→6 by a small number of single-unit β-D-Glcp side-chains, it′s also observed that the (1→3)-linked β-D- glucan contained a triple-helical conformation, which was composed of a repeating unit with a structure as below:→3)-β-D-Glcp-(1→3)-[β-D-Glcp-(1→3)-]_n-β-D-Glcp-(1→.↑6/1β-D-Glcp