Abstract: Feruloyl oligosaccharides(FOs)were prepared by enzymatic hydrolysis of brewer’s spent grain(BSG). The composition and antioxidant activities of FOs were determined. Results showed that,the ferulic acid content was 3.06%(w/w),the total sugar contents was 65.50%(w/w)in FOs. The sugar composition was xylose and arabinose. The solid samples of FOs were analyzed by ultraviolet spectroscopy and infrared spectroscopy,it was proved that solid sample was sugar esters. FOs had good scavenging capacity against hydroxyl radicals,1,1-diphenyl-2-picrylhydrazyl(DPPH)free radicals and superoxide anion radicals,and the reducing power was superior to that of ferulic acid and xylooligosaccharides. At 8 mg/mL,the scavenging rates of FOs on hydroxyl radicals,DPPH free radicals and superoxide anion radicals were 79.40%,84.40% and 59.40%,respectively,and the reducing power was 1.22.