Abstract: In order to find out the differences in field microclimate in Zhaotong tobacco producing area, the field microclimate data and the corresponding tobacco samples were collected and analyzed from 11 representative regions in Zhaotong tobacco producing areas. The results showed that the field microclimate had significant differences among tobacco planting areas in Zhaotong. There were correlation between tobacco leaf chemical composition (including total volatile acids, starch, potassium oxide, water soluble chloride, total alkaloids, petroleum ether extract, sugar, amino nitrogen, total polyphenols, total ash) and climatic factors (including temperature, relative humidity, precipitation, sunshine hour, and solar radiation) during tobacco leaf mature period (July-September). The 11 representative zones of 8 tobacco producing areas in Zhaotong were divided into 3 types according to hierarchical cluster analysis. The type I was in dam area of Zhaoyang and Ludian, which had low temperature, relative humidity 62.8%-74.3%, lower precipitation, longer hours of sunshine, and larger solar radiation. The type Ⅱ was in Qiaojia tobacco growing areas and Ludian Niulan river tobacco growing areas, which had higher temperature, relative humidity 58.2%-71.5%, more precipitation, longer hours of sunshine, and larger solar radiation. The type Ⅲ was the other mountain tobacco growing areas, which had the temperature between type I and type Ⅱ, relative humidity 69.1%-79.6%, more precipitation, shorter hours of sunshine and smaller solar radiation.