Abstract: The harvested tobacco leaves of K326 were treated with bacterial suspension of strain K7 and K3(Arthrobacter spp.) and their nicotine contents were analyzed after flue-curing.The results indicated that the nicotine contents reduced in all treatments comparing with the control,the reduction rate in tobacco leaves grown in paddy field was slightly higher than that grown in hillside land,and the reducing effect of K7 was better than that of K3. For tobacco grown in paddy field,the reduction rates in lower,upper and middle leaves treated with K7 were 39.7%,29.5% and 28.4%,respectively,and those treated with K3 were 34.9%,29.2% and 26.1%,respectively.The sensory evaluation of cigarettes made of each single grade tobacco showed that bacterial suspension could increase the aromatic quality and volume of tobacco leaf(especially for middle leaves),reduce irritation and strength,and improve aftertaste.