[Objective] To research the correlation between elongation and main chemical component of tobacco leaves,and to find a method to detect the content of main chemical component. [Method] The elongation rate and main chemical composition of different parts of 66 fluecured tobacco samples were detected,which were at different grades and obtained by different baking methods. Correlation analysis was carried out. [Result] Elongation rate of flue-cured tobacco showed extremely positive correlation with total nitro...