Abstract: In order to investigate the effects of pH value of cut tobacco on nicotine in and smoking quality of cigarette smoke,cut tobacco of two brands of cigarette was treated with 0.2 mol/L HCl and 0.5 mol/L NaOH aqueous solutions,respectively,and then the pH value of and total nicotine in cut tobacco and the total nicotine and free-nicotine in tobacco smoke were determined,and the sensory quality was evaluated.The results showed that:1)there was no significant effects of pH value of cut tobacco on the total nicotine in tobacco and its smoke;2)the free-nicotine in tobacco smoke was extremely significantly positively correlated with the pH value of cut tobacco of the same brand;3)the impact of tobacco smoke enhanced with the increase of pH value of cut tobacco,while the other sensory quality indexes changed a little.It was concluded that free-nicotine in and impact of tobacco smoke could be adjusted by changing the pH value of cut tobacco within a certain range.