The nicotine contents of flue-cured tobacco samples were determined by continuous flow method, and the sensory quality was assessed quantitatively to study the spatial distribution characteristics of nicotine contents and its quantitative correlations with the evaluation indices of aroma and taste. The results showed that the mean value of nicotine content in flue-cured tobacco leaf of B2F, C3F, X2F was 3.90%, 3.10%, 2.15%, respectively. The samples with nicotine content above 3.5% accounted for 73.51% in B2F,24.14% in C3F, 2.01% in X2F. The nicotine content in upper leaves was higher in partial areas of Hunan Province. The nicotine content of flue-cured tobacco leaf was higher in the northwest Hunan than the south, and decreased gradually from northwest to south. Nicotine content exhibited a linear correlation with aroma volume, offensive odor, density, irritancy and after-taste, yet a curvilinear with aroma quality, total aroma, strength, taste and sensory quality. The increase of nicotine content might lead to the increasing aroma volume and density, the enhancing offensive odor and irritancy, and the unfavorable after taste. The aroma and taste was favored when nicotine content ranged from 2.5% to 3.5%, while the optimum sensory quality appeared when the nicotine content was 3.0%.