Abstract: A bacterial strain with a high ability of nicotine degrading was isolated from the soil near Kunming Cigarette Factory.The bacteria could grow well in the culture medium with nicotine as its sole source of carbon and nitrogen.More than 80%of the nicotine in the liquid medium contained 0.4%nicotine was degraded after fermentation for 78hrs.Meanwhile, the color of the liquid medium turned from colorless, through blue, dark blue, and black, to brown.Based on its ecological character and physiochemical analysis, the strain was identified preliminarily as a member of Athrobacter sp.The nicotine in 100g of Yunnan B3F cut tobacco sprayed with 2 mL of enzyme liquid (10.15mg protein per mL)of the bacteria and fermented for two days decreased by 15.2%;and that in the same tobacco sample sprayed with the bacterium liquid (109cfu per ml)and fermented for seven days decreased by 22.1%.