Abstract: To establish an objective and accurate method for discriminating tobacco types (including tobacco leaf, cut tobacco, tobacco dust, etc), nonlinear chemical characteristic spectrum technique was used to obtain the corresponding electric potential-time (E-t) function curves from tobacco samples. The key factors affecting chemical oscillation system were optimized, and the repeatability of the method was investigated. The nonlinear chemical characteristic spectra of tobacco leaves of five types (flue-cured tobacco, red sun-cured tobacco, yellow sun-cured tobacco, oriental tobacco and burley tobacco) were characterized under the optimized conditions, and the types of six confiscated tobacco samples were analyzed to validate the established method. The results showed that:1) The optimized conditions were bath temperature 45℃, stirring speed 800 r/min, sample weight 0.50 g, and volume of 0.8 mol/L NaBrO₃ solution 3 mL. 2) The method achieved a high consistency with an average similarity of 0.982 2 for the five spectra obtained from the same sample. 3) The tobacco samples of five types displayed unique spectra with total similarities ranged from 0.749 3 to 0.883 9. 4) The types of six confiscated tobacco samples discriminated by the established method agreed with those determined by a traditional panel test. This novel method is intuitive, accurate, with good repeatability, and suitable for identifying and discriminating confiscated or counterfeit tobacco.