Xylose reductase gene (xyl1), xylitol dehydrogenase gene (xyl2) from Piehia stipitis and xylose transaldolase gene of Saecharomyces cerevisiae (tal 1) were constructed on expression vector pAUR123 by the method of concatenating co-expression to build a recombinant Saceha- romyees cerevisiae strain. Based on opening the path of xylo-oligosaccharide transformating to xylulose, with super expression of xylose transaldolase, the three enzyme genes expressed successfully after imported into Soccharomyces cerevisiae INVSc1. Then such strain used xylose as the sole carbon source for limited-oxygen fermentation, and it could use xylose prelimilarily. The results showed that the utilization rate of xylose was 77.4 %, but the yield of ethanol was only 0.04 mg/mL. Besides, the effects of three enzyme gene co-expression on ethanol yield produced by xylose fermentation by Saccharomyces cerevisiae were invesigated. And it was found that the three enzymes played key roles in xylose utilization, their over-expression would cause a large number of accumulation of xylitol, and further result in low ethanol yield.%将来自树干毕赤酵母的木糖还原酶基因（xyl1）、木糖醇脱氢酶基因（xyl2）和酿酒酵母自身的木糖转醛酶基因（tdl1），通过串联共表达的方法构建到表达载体pAUR123上，构建了1株重组酿酒酵母。该菌在打通木糖向木酮糖转化通路基础上，超表达木糖转醛酶。该菌以木糖为唯一碳源进行限氧发酵，能初步利用木糖。结果表明，木糖的利用率为77．4％，但乙醇产率仅为0．04mg／mL。同时探讨了3种酶共表达对酿酒酵母发酵木糖生成乙醇的影响，发现3种酶对木糖的利用起关键性的作用，其过量表达导致木糖醇大量积累，乙醇得率降低。
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