Abstract: Using 0.01 mol/L NaH₂PO₄(PH 1.20)buffer solution as acidulant,acetone as extracting solvent,P_bromophenacyl bromide as deriving agent, the formic, acetic and lactic acids in eight tobacco sampleswere simultaneously determined by HPLC at the wavelength of 255 mm with Waters C₁₈ column(3.9×mm,5μm)at 35℃ and CH₃OH-CH₃ CN-H₂O as mobile phase at the flow rate of 1.0 mL/min.The results showed that:1)the recoveries of the threee organic acids ranged from 97.9% to 106.5% with the relative standard deviations of 5.17% to 7.33% and the limits of detection of 1.32 to 3.30μg/mL;2)there was no obviously difference between the acetic acid contents in the two cigarette samples and the six tobacco leat samples, while the contents of formic and lactic acids in the cigarette sampleswere farhighter, especially, lacticacid contentwas 2 to 8 times that in the leaf samples.