Abstract:In order to explore the changes of tobacco quality in different sub-climatic zones, 5 flue-crued tobacco varieties including K326, Y87, Y99, NC102 and NC297, were chosen as experimental material, which were separately planted on 3 main sub-climatic zones like north subtropical zone,warm temperate zone and mid-temperate zone in Kunming. The relationship between smoking quality and carbohydrate-related indexes were analysed in the middle leaves. The results suggested that sub-climatic zone was a very important ecological factor for the quality of tobacco leaves. The scores of smoking quality and 6 carbohydrated-related indexes were highest in the warm temperate zone, followed by the north subtropical and mid-temperate zone in succession. The score of smoking quality presented a positive correlation with the indexes above, and it had a significant positive correlation with starch, total sugar and the ratio of sugar and nitrogen, and an extreme positive correlation with the difference between total sugar and reducing sugar.