Abstract: Six tobacco varieties were used for the field experiment which was carried out at Zhaoyang district， Qiaojia county， and Zhenxiong county of Zhaotong city in Yunnan province. Agronomic characteristics differences among varieties at different ecoenvironments were compared， and the character of fluorescence was measured by portable modulated chlorophyll fluorometer Mini-PAM. The results showed that tobacco leaf was the most sensitive organ in response to environment. Because of the plenty of rainfall and abundant solar radiation， leaf length， leaf width and leaf area of tobacco in Qiaojia were bigger than that in Zhaoyang and Zhenxiong. Because of the relatively heavy arid climate in Zhenxiong in early and middle July， maximum photochemical quantum yield and effective photochemical quantum yield of almost all varieties in this experimental site were the lowest. Differences of actual photochemical quantum yield and electron transfer rate of K326 and Yunyan 203 among the 3 experimental sites were consistent， indicating the presence of similar mechanisms in response to the environment in light energy capture and electron transport of the two varieties. NPQ of all varieties were different from each other in the points， reflecting the diversity and plasticity of environmental adaptation.

Key words: Tobacco, Climate condition, Agronomic trait, Chlorophyll fluorescence