Abstract: In order to reveal the basic chemical constituents of the aroma type style of tobacco of Xuanwei, correlation analysis and multivariate analysis of variance were used to study the relationship between the major chemical indices and representativeness of flavor types of 158 representative samples of upper leaves of flue-cured tobacco from 22 villages and towns. The results show that the high representativeness of flavor types of tobacco leaves had the following characteristics, content of total sugar, reducing sugar, starch and the difference between the total sugar and reducing sugar, the ratio reducing sugar to nicotine were slightly high and content of nicotine, total nitrogen, total volatile alkali, scopoletin, calcium, chlorine, sulfur were slightly low. But the trend that the representativeness of upper leaves changed with the different value ranges of major chemical indices were not linear. The proper ranges of major chemical indices with higher representativeness of flavor type of upper leaves were ascertained: total sugar: 27%-37%, reducing sugar: 21%-30%, starch: 4%-6%, the difference between the total sugar and reducing sugar: 8%-12%, total nitrogen: 1.6%-2.0%, nicotine: 2.2%-3.8%, total alkali: 0.30%-0.45%, the ratio of reducing sugar to nicotine: 8-12, scopoletin: 0.05-0.15 mg/g, the upper limits of content of calcium: 3.2%, chlorine: 0.4%, and sulfur: 0.6%.