Abstract: With wheat bran as the raw material, β-glucan was extracted by alkaline extraction.The crude extraction of β-glucan was purified gradually by adding ( NH4) 2SO4and using DEAE Sepharose CL- 6B anion- exchange chromatography as well as Sepharose CL- 4B gel filtration chromatography, and components A1 and A2ofβ-glucan were obtained after purification. The purity of β- glucan was researched by UV scanning and high performance gel permeation chromatography analysis.The relative molecular weights of β-glucan components A1, A2 were respectively 4.87 × 105 ( purity was 98.57%) , 6.13 ×104 ( purity was 97.03%) .So homogeneous β-glucan components with high purity were obtained after purification. After β- glucanase enzymatic hydrolysis β- glucan component A from anion- exchange chromatography, the oligosaccharide composition was analysised by HPLC.The results showed that: the oligosaccharide constitutions were primarily maltotriose and maltotetraose. What's more, there were a small amount of glucose, maltose and maltopentaose.