Calcium and magnesium are elements that have important influence on yield and quality of flue-cured tobacco. In this study, the contents of exchangeable calcium and magnesium in different soil types and their effects on flue-cured tobacco quality in Hunan tobacco-planting areas were analyzed. The objectives of this study were to supply a scientific basis for the production of high-quality flue-cured tobacco and balanced fertilization in Hunan tobacco-growing areas. The results indicated that: (1) There existed significant differences among different soil types for the contents of exchangeable calcium and magnesium. The average content of exchangeable calcium was 8.87cmol/kg, and was the highest in red soil type. The average content of exchangeable magnesium was 1.16cmol/kg, and was the highest in yellow brown soil type. The ratio of exchangeable calcium to magnesium showed the trend of red soils (11.74) > paddy field (10.25) > yellow soils (6.84) > yellow brown soils (6.14). It is suggested to use magnesium fertilizer for red soils and paddy field. (2)The average content of calcium in tobacco leaves was (21.93±4.37) g/kg, and the average content of magnesium in tobacco leaves was (2.52±1.26) g/kg. Both had extensive variation. (3) By using the method of ANOVA, the change was analyzed for the contents of calcium and magnesium in tobacco leaves along with the contents of exchangeable calcium and magnesium in soils. In total, the content of calcium in tobacco leaves increased significantly with the content of exchangeable calcium increasing and the content of exchangeable magnesium decreasing in soils; the content of magnesium in tobacco leaves increased significantly with the content of exchangeable magnesium increasing, and there was no significant correlation with the content of exchangeable calcium in soils. (4) The canonical correlation analysis showed that the decrease of exchangeable magnesium in soils increased the content of potassium in tobacco leaves, and consequently made good balance between potassium and magnesium in tobacco leaves. (5) The correlation analysis between the contents of exchangeable calcium and magnesium in soils and other chemical components in tobacco leaves showed that exchangeable calcium in soils was good for the absorption of B and Cl, but made against absorbing N, Zn and Mn significantly. Meanwhile, exchangeable magnesium in soils was good for the accumulation of total sugar, B and Mn, but made against absorbing N, P, Fe and Zn significantly.