Nicotine is the principal alkaloid in tobacco, and nornicotine, anabasine, anatabine, myosmine, nicotyrine and 2,3'-dipyridyl are the minor alkaloids in tobacco. Because of their importance, developing a fast and accurate quantitative method to analyse tobacco alkaloids is necessary. A method for the determination of these seven alkaloids in tobacco was established based on heart-cutting multidimensional gas chromatography (MDGC). The alkaloids were extracted by 10%NaOH/tert-butyl methyl ether (TBME) and determined by MDGC with flame ionization detection (FID). The separation of alkaloids and the reliability of quantitative results were improved significantly by MDGC. The recoveries for the alkaloids ranged from 90% to 110% and relative standard deviation based on five individual preparations were lower than 5%. Tobaccos of four different types were analyzed, including 86 flue-cured tobaccos, 12 Burley tobaccos, 17 yellow sun-cured tobaccos and 30 Oriental tobaccos. The results showed that the contents of alkaloids varied with tobacco types, which in the order of contents of total alkaloids, nornicotine and anatabine were Burley>yellow sun-cured>flue-cured>Oriental. The contents of nicotine, anabasine, nicotyrine and 2,3'-dipyridyl were similar in Burley and yellow sun-cured tobaccos, which were higher than those in flue-cured and Oriental tobaccos. Among the minor alkaloids, nornicotine was the highest in Burley tobacco, anatabine highest in yellow sun-cured and flue-cured tobaccos, while both nornicotine and anatabine were the highest in Oriental tobacco. The ratio of nornicotine to anatabine in yellow sun-cured tobacco was close to that in flue-cured tobacco. Myosmine is positively correlated with nornicotine in all types but Oriental tobacco. The results also showed that alkaloid content significantly related with tobacco style and quality.