Abstract: 18 of free amino acids in tobacco were simultaneously determined by high performance anion-exchange chromatography with integrated pulsed amperometric detection method. The results showed that the recoveries for 18 amino acids were in the range of 80%-115％, the detection limits for 18 amino acids were 0.03-0.75 μg/mL and the calibration graphs of peak area for the analyses were linear over about three orders of magnitude with a correlation coefficient of 0.9900-0.9992. The method was applied to determine 18 free amino acids in tobacco with satisfactory results. The method was employed to determine 18 free amino acids in flue-cured tobacco, burley tobacco and oriental tobacco. The method was also employed to determine successfully 18 free amino acids of different brands of domestic cigarettes and overseas cigarettes.