Abstract: A method combining microwave-assisted derivatization with fast gas chromatography(GC) was developed for rapidly determining the contents of polybasic acids(oxalic acid,malonic acid,fumaric acid,succinic acid,malic acid and citric acid) and higher fatty acids(palmitic acid,stearic acid and linoleic acid) in tobacco,and the contents of these acids in ten flue-cured tobacco samples and ten cigar filler tobacco samples were determined.The results showed that:1) The optimal pretreatment conditions were using 10% sulfuric acid-methanol as esterification reagent and CH2Cl2 as extraction agent while the power of microwave increased at a rate of 20 W/s to 1200 W(remaining for 1 min).2) The time for fast GC analysis was 8.81 min,the calibration curves of target compounds displayed good linearity(r²>0.99),the standard addition recoveries ranged from 83.18% to 114.17% with RSD less than 5%.3) The contents of organic acids in flue-cured tobacco and cigar filler tobacco were quite different,the contents of polybasic acids(excluding malic acid) were higher in cigar filler tobacco,while the contents of higher fatty acids(excluding stearic acid) were higher in flue-cured tobacco.This method is rapid,accurate and suitable for the determination of polybasic acids and higher fatty acids in tobacco.