In order to investigate quality characteristics of tobacco leaves in Longyang area of Yunnan Baoshan,the physico-chemical characteristic of tobacco leaves before and after flue-curing from Yunyan85, K326 and Hongda were researched. The results showed that under the ecological conditions of Baoshan Longyang,the moisture content in flue-cured tobacco leaves of Yunyan85 was higher than that of K326, while it in vein of K326 was higher than that of Yunyan85. There were more bound water in the flue-cured tobacco leaves of Hongda and more polar organic compounds compared to Yunyan85. Before roasting, tobacco leaves of Yunyan85 and K326 accumulated a wealth of starch and protein,but Hongda had less of it. As a result, level of the total sugar,reducing sugar, differences between two kinds of sugar and amino acids, nicotine in leaves of Hongda were lower compared to Yunyan85 and K326 after baking. Compared with Yunyan85 and K326,content of non-reducing polysaccharide was low and variations of sugar-nicotine ratio of Hongda after flue-curing was small. The ratio of reducing sugar-amino acid and amino acid- nicotine of Hongda tended to decrease. All of these characteristics proved that Hongda had good quality and excellent industrial usability.