Abstract: The thermal mass loss and pyrolysis products of phenylethyl β-D-glucopyranoside were investigated with thermogravimetry and differential thermal analysis (TG-DTA) and online pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The TG curve showed that the largest mass loss occurred from 240 to 350℃, within that temperature range, the sample lost nearly all its mass. The DTA curve illustrated that melting temperature was 107.63℃, and pyrolysis temperature was 325.29℃ . The main pyrolysis products were benzenoid and heterocyclic compounds. The number of pyrolysis products increased with the rise of temperature. This study provided a reference for investigating the transformation behavior of phenylethyl β-D-glucopyranoside during cigarette combustion.