Abstract: In order to improve the content and purity of β-glucan in the barley bran,the barley bran β-glucan was prepared by fermentation. Single factor and orthogonal experiments were used to optimize the extraction conditions,and physical and chemical properties of the β-glucan which obtained by fermentation were analyzed. The optimal process parameters for the extraction of barley bran β-glucan by fermentation method were as follows:Inoculation with 0.05% high active dry yeast,ratio of material to liquid 1:6,fermentation temperature 32℃,fermentation time 34 h. The yield of β-glucan produced under optimal conditions was 5.21%±0.02%,which was increased by 60.8% compared with the traditional water extraction method,and the purity was 91.21%. The physical and chemical analysis of the barley bran β-glucan extracted by fermentation method was characterized by monosaccharide composition mainly D-glucose,and its average relative molecular mass was 1.366×10⁵. The barley bran β-glucan monosaccharide extracted by water extraction method was consisted of D-arabinose,D-galactose,D-xylose,D-mannose,D-glucose. It's average relative molecular mass was 7.759×10⁵.