Abstract: In order to study the pyrolysis differential between tobacco of different stalk positions, growing areas and crop years, 20 representative tobacco samples were collected and tested by TGA (Thermogravimetric analyzer) to obtain their DTG curves, the differences of which were assessed by NRMSE (Normalized root-mean-square error), and the influence degrees of crop year, growing area and stalk position were determined by ANOVA. The results showed that stalk position and growing area by province significantly affected the pyrolysis differential, while the crop year and growing area by county/city level did not.