The variation of main chemical indicators of flue-cured tobacco in the upper, middle and lower parts of three main varieties (K326, Yunyan87, Honghuadajinyuan) in five main producing areas (Changning district, Longling district, Longyang district, Shidian county, Tengchong city) of Baoshan, Yunnan province from 2010 to 2017 were analyzed. The results showed that variations were widely existed in the main chemical components of flue-cured tobacco among different years, in that variation coefficient was large and stability was poor in chlorine content, potassium-chlorine ratio and sugar-alkali r...