Abstract: The enzymatic hydrolysis residues of xylan was pretreated under high temperature from 160℃ to 180℃, then the filtrate of the pretreated suspension was enzymatically hydrolysed. Under the optimal condition of pretreatment for 30 min at 180℃, 42.54% of xylan residues could be decomposed efficiently and the yield of xylooligosaccharides(XOS)was 32.13% of the total carbohydrates of the supernatant. After enzymatic hydrolysis, the yield of XOS could be up to 84.93% of total carbohydrates of the supernatant.

Key words: xylanase, xylooligosaccharide, enzymatic hydrolysis