The decolorization process of xylo-oligosaccharides from corncobs was studied. xylo-oligosaccharides were extracted from corncobs by complex enzyme, which consisted of xylanase and cellulose. The decolorization process of xylo-oligosaccharides extract was optimized with activated carbon. Result indicated that the optimal parameters were as follows: activated carbon amount 20%, total soluble sugar content 11 mg/mL, at 40 ℃ for 30 min. Under the optimal conditions, the decolorization rate and the loss rate of reducing sugar were 68.93 % and 34.75 %, respectively. The yield of xylo-oligosaccharides after ethanol precipitation was 11.58%.