Varieties K326, Xiangyan3, Yunyan87 and YZ206–9 were selected in Guiyang tobacco–growing area of Hunan province to determine the chemical composition and neutral aroma substances in tobacco leave. The results showed the content of total sugar, reducing sugar and starch in Yunyan87 was the highest (30.26%, 28.11%, 4.74% respectively), K326 had the highest content of nicotine (3.00%)，Xiangyan 3 had the highest content of total nitrogen (2.16%), YZ206–9 had the highest content of petroleum ether extract (5.46%). Chemical components contents in leaves from 4 varieties of flue–cured tobacco are in line with standards of quality tobacco except for total sugar, reducing sugar and chlorine content which exceeded the standard range of high quality tobacco. The ratio of nitrogen to nicotine and the ratio of sugar to nicotine are in the range of high quality tobacco, while the ratio of potassium to chlorine was below the standard of high quality tobacco. The varieties of neutral aroma constituents in leaves from 4 varieties of flue–cured tobacco were the same, but the contents of which showed significant difference. The total amounts of neutral aroma substances, the degradation products of most of the plastid pigment, the products of Maillard reaction and the content of phenylalanine degradation products in Yunyan87 were the highest, which significantly higher than those in other varieties. K326 had the highest content of cembranoids product, which significantly higher than that of Yunyan87 and Xiangyan3. Xiangyan3 and K326 showed similar contents in most of Maillard reaction products and degradation products of phenylalanine, with no significant differences. Contents of Maillard reaction products and phenylalanine degradation products in YZ206–9 were generally lower than those in other varieties. There are difference both in proportions and contents of chemical constituents and neutral aroma substances among different flue–cured tobacco varieties.