Abstract: The influence of the temperature,inoculum time,p H,methanol concentration and induction time on the xylanase production of pichia recombinant bacteria were studied. The response surface optimazation was designed on the basis of the single factor experiment,and the small squares quadratic regression equation was fitted out according to the results to discuss the influence of the various factors on the xylanase enzyme activity. The optimum fermentation culture conditions were as follows:inoculum age 31 h,induction time 104 h,methanol concentration induced by 1%,fermentation starting p H4.0,induction temperature 30 ℃. On this condition,the result of the experiment for xylanase enzyme activity was 43526.3 U/mg.