Two water-soluble polysaccharide fractions named as GLPD2 and GLPD2were isolated and purified from the same Ganoderma Lucidum body which was collected from Jiangxi province. The GPC and SEC-LLS results indicated that GLPD1 and GLPD2 were high purity, moreover, their molecule weights could both reach above 5×106. Their primary structural features and conformational properties were characterized by infrared spectrometry and SEC-LLS. The data obtained indicated that GLPD1 and GLPD2 may both be β-glucan configuration with pyran glucan groups. What's more, conformational analysis detected by SEC-LLS showed that GLPD1 and GLPD2 had rather tight structure with high degree of branch. However, PMP-HPLC analysis found out that GLPD1 and GLPD1 were quite different from each other. To clarify this, the Monosaccharide composition mole pencentage ratios were listed. GLPD1∶Man∶GlcN∶Rib∶Rham∶GalUA∶GalN∶Glc∶Gal∶Xyl∶Fuc=3.7∶0.8∶0.16∶6.8∶0.7∶0.29∶77∶9.27∶0.16∶1.1; GLPD2∶Man∶GlcN∶Rib∶Rham∶GalUA∶GalN∶Glc∶Gal=10.6∶2.0∶0.97∶10.72∶0.65∶0.99∶64.51∶9.52. In the end, compared the immunological activity with normal mice spleen lymphocyte proliferation promotion activity which were significant difference. It provide reliable basis for the culture of this kind of Ganoderma Lucidum.