Abstract: Eurotium cristatum, a fungus from Fuzhuan brick tea, was separated and identified.In order to improve the quality of tobacco, the fungi was made for different concentrations of spore suspension and incubated to cloud 85, B3 F flue-cured tobacco leaf at constant related humidity ( 70% ± 2%) for 50 days.The results of chemical analysis and artificial smoking showed that the sugar, water soluble total sugar with a overall increasing.The total potassium were reduced and sugar /alkali, nitrogen /alkali tended to the optimal ratio at condition of 30℃, spore concentration was 1 × 107 cell /mL.At the same time, the aroma quality and aroma quantitative tended to be better; mixed gas, nicotine content and irritation plump were reduced; sweetness and sophistication were increased. The overall quality of tobacco had been improved significantly.