Abstract: An aromaproducing strain GXY35 was isolated from 14 kinds of tobacco leaves， and the aroma components were analyzed by gas chromatographymass spectrometry （GC/MS）. The strain was identified as Klebsiella sp. from physiological and biochemical characteristics and 16S rDNA. The content of 4vinylgualacol in fermentation broth was the highest. On the basis of single factor test， the fermentation condition of strain was optimized by orthogonal experiment. The optimal fermentation condition was as follows: the solidliquid ratio of 1∶20， the inoculums size of 12%， the fermentation temperature of 37 ℃， the fermentation time of 72 h， and the initial pH of 7.0. Under the optimal fermentation condition， the content of the characteristic favoring substance of 4vinylgualacol was 0.725 mg·mL-1.

Key words: bioflavours, characteristic flavoring substances, aromaproducing fermentation, flavor compounds in cigarette