Abstract: Aging tobacco leaves in sealed and oxygen-reduced environment were unsealed in an air environment and a nitrogen-filled low-oxygen environment respectively to study the impact of the unsealing process on the chemical components of the tobacco leaves. Gas chromatographymass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) were used as detection methods to examine changes in the contents of volatile aroma components, carotenoids, nicotine and amino acids. The results show that the contents of carotenoids, nicotine and amino acids in the precursors of tobacco leaves unsealed in a nitrogen-filled low-oxygen environment remain basically the same as the initial content within one month, and some volatile aroma components would increase significantly. When unsealed in the air, the content of some nicotine and amino acids in the precursor will change slightly, but the volatile aroma components will remain stable and basically unchanged. The results of this study can provide a reference for determining a reasonable storage period and environment after tobacco leaves are unsealed.