Abstract: 【Objective】In order to understand the quality characteristics of tobacco leaves from new tobacco growing areas in Yunnan and improve the industrial usability of tobacco leaves, the characteristics of main chemical components in flue-cured tobacco leaves were analyzed.【Method】288 samples of the upper, middle and lower tobacco leaves (B2F, C3F, X2F) during 2011-2018 were collected from Guangnan, Jingdong and Shuangjiang. The main chemical components in tobacco leaves were determined and their relationships with cigarette smoking quality were studied.【Result】The chlorine contents in all the upper, middle and lower tobacco leaves during 2011-2018 collected from Guangnan, Jingdong and Shuangjiang were relatively low in general. The reducing sugar contents in 41.92% of the middle leaves were higher than 26%, and the nicotine contents in 33.33% of the upper leaves were higher than 3.5%. Higher nicotine contents in the upper leaves and higher reducing sugar contents in the middle leaves were the main factors influencing the chemical componentcoordination of tobacco leaves from the 3 tobacco planting counties of new tobacco growing areas. The contents of potassium and chlorine in tobacco leaves during 2011-2018 were relatively stable in the 3 tobacco planting counties. However, the contents total sugar of reducing sugar in middle and upper leaves showed an increasing trend since 2013, and the biggest increase was up to 16.02%. The contents of nicotine and total nitrogen showed a downward trend since 2013, and the biggest decrease was 22.07%. The grey correlation analysis indicated that the contents of total nitrogen and reducing sugar were the main chemical component indicators influencing the total scores of smoking quality.【Conclusion】There were significant differences in the characteristics of main chemical components in tobacco leaves from 3 tobacco planting areas of Yunnan. It is recommended that total nitrogen contents of tobacco leaves in Shuangjiang should be appropriately raised and reducing sugar contents be reduced, while the coordination of chemical components of tobacco leaves in Guangnan can be improved by controlling the contents nitrogen and nicotine .