Abstract: Response Surface Methodology (RSM) was used to optimize the processing of enzymatic preparation of Xylooligosaccharide from wheat bran.On the basis of, select the level of experimental factors.According to the result of single factor tests and the experimental design principles of the Box-Benhnken central composite design (CCD) , using four factors and three levels of response surface methodology to analyse each factor.The reducing sugar content in response to the value of establishing mathematical model, the optimum conditions were as follow:the pH was 6.3, zymohydrolysis time was 76min, the accession of the xylanase was 790U/g, zymohydrolysis temperature was 63.3℃.Under this condition, 5.15mg/mL reducing sugar was produced.Enzymatic method for the preparation of Xylooligosaccharide worked well, with relatively higher yield of Xylooligosaccharide.