The cDNA sequence of beta-xylanase gene (xynB) was cloned from Aspergillus niger UV-11. It was inserted into the yeast expression vector and the recombinant plasmid pAX2 was obtained. The plasmid pAX2 was introduced into an industrial S. cerevisiae 2.346 and integrated into yeast genome by co-transformation of a YEPtype plasmid pBEJ16 carrying G418 resistance. The stable engineered yeast strain XY2 was obtained. It could express and secret extracellular xylanase, and enhance the alcohol production in wheat flour fermentation compared with the host strain S. cerevisiae 2.346.