This study was carried out to develop the method of alkaloids analysis and investigate the kinds and contents of alkaloids in flue-cured, burley and oriental tobacco leaves using developed analytical method. The developed analytical method of alkaloids was as followed : Tobacco sample was treated with acid(pH 2∼3) and extracted with chloroform to remove chemical components except alkaloids. Sample solution was treated with alkali(pH 12∼ 13) and was extracted with chloroform to obtain alkaloids from sample solution. After extraction of alkaloids from tobacco leaves, alkaloids were separated and identified by GC, GC/MS using SE-54 fused silica capillary column. Nicotine, nornicotine, myosmine, 9-nicotyline, anabasine, anatabine, 2, 3-bipyridyl, cotinine, formyl nornicotine, acetyl nornicotine and formal anatabine were isolated and identified from the extracts of tobacco leaves. The contents of alkaloids were burley > flue-cured > oriental tobacco leaves, but oriental tobacco leaves were higher nornicotine, cotinine, formyl nornicotine and acetyl nornicotine contents than those of flue-cured tobacco leaves. The burley tobacco harvested in Korea was higher nornicotine contents by 2-6 times in the portions of cutter, leaf and tips position than that of burley tobacco(B3F) harvested in V. S. A.