Abstract: In order to explore the main chemical compositions change of flue-cured tobacco among years in China, from 2007 to 2013 we collected 40 139 samples from 12 Provinces, and determined their main chemical component contents. The results showed that the variation coefficients of chlorine content and K/Cl of flue-cured tobacco were greatest among all of the indicators, followed by variation coefficient of K content, ratio of reduce sugar to nicotine and nicotine content. Variation coefficient of total sugar, reduce sugar, total nitrogen and ratio of reduce sugar to total sugar. The main chemical components contents were suitable and harmonious. It was considered that change in reduce sugar content, chlorine content and ratio of reduce sugar to total sugar were obvious, and reduce sugar content and ratio of reduce sugar to total sugar decreased gradually, chlorine content increased gradually.