Germinated brown rice （GBR） was used as the test material， germinated brown rice polysaccharides （GBRPs） were extracted， the components were purified and isolated， the structure of different GBRPs components were analyzed. The purity， molecular weight， monosaccharide composition， chemical bond composition and glycosidic bond structure of GBRPs were determined by UV-Vis， gel permeation chromatography（GPC）， high performance liquid chromatography （HPLC）， Fourier infrared spectroscopy （FTIR） and nuclear magnetic resonance hydrogen spectroscopy （1H NMR）. The results showed that four components of WPS， SPS-1， SPS-2 and SPS-3 were isolated from GBRPs. WPS consisted of rhamnose， xylose， arabinose， mannose and glucose， SPS-1 consisted of mannose， rhamnose and glucose， SPS-2 consisted of rhamnose， arabinose， mannose and glucose and SPS-3 consisted of rhamnose， arabinose， and glucose. FTIR spectra showed that each component contained the characteristic absorption peak of polysaccharide. WPS was mainly composed of pyran-type sugar ring. The pyran-type and furan-type sugar ring coexisted in SPS. 1H NMR analysis showed that WPS was α-configuration containing pyran rings. Furan and pyran sugar ring with α- and β-configuration were presented in SPS. SPS-1 had the highest inhibition rate on α-glucosidase， and it could also increase the activity of hexokinase and pyruvate kinase in insulin-resistant HepG2 cells， the glycogen content of model cells was also significantly increased， which proved its hypoglycemic activity.