Abstract: The pyrolytic properties of geraniol were studied by the hyphenation of pyrolysis-gas chromatography and mass spectrometry (Py-GC-MS). Helium was used as carrier gas, and pyrolysis of the geraniol sample was performed separately at temperatures of 300, 400, 500, 600, 650, 700 and 800 ℃. The pyrolyzates obtained were directly introduced into the GC-MS instrument and analyzed qualitatively and semi-quantitatively. It was found that geraniol was completely pyrolyzed at 700 ℃ and there were 87 pyrolyzetes obtained. Based on the main pyrolytic products obtained and on the change of relative contents of the products, a preliminary discussion on the mechanism of pyrolysis of geraniol was given, and a theoretical basis was proposed for the evaluation of action of the essence in the process of cigarette burning.