Abstract: To study the quality and stability of tobacco casings, the sulfuric acid-methanol derivatization fingerprints of tobacco casings were established based on gas chromatography-mass spectrometry. A correlation coefficient method and a cosine including angle method were used to calculate the similarity between the abnormal samples and the standard samples. The abnormal samples included different batch samples, heated samples, mixed samples and diluted samples. Based on the test results from 13 batches, the similarity threshold was defined and used as the basis for assessing the quality stability of tobacco casings. The results of this method were compared with those of traditional physical and chemical indices and olfactory methods. The results showed that: 1) The fingerprints of tobacco casings from different batches had good stability and high similarity. 2) The similarity calculated by weighting the common peaks of each fingerprint based on the entropy method was superior to the unweighted method, and the correlation coefficient method was superior to the cosine including angle method. 3) Combined with the similarity calculation results and thresholds, the qualified tobacco casing samples and the abnormal samples, including heated samples, mixed samples and diluted samples, could be distinguished, especially at higher mixing and dilution ratios. 4) This method was more sensitive to evaluate the quality and stability of tobacco casings than the methods of physical and chemical indices and olfactory analysis, especially for samples with minor differences. This method can comprehensively and accurately monitor the quality of tobacco casings, and provide technical support and reference for evaluating the quality stability of tobacco casings.