Abstract: In order to investigate the influences of the physical parameters of the paper-base in paper-making process reconstituted tobacco on its pyrolysis behavior, the formation of pyrolyzed gas phase products of 4 paper-bases with different physical parameters were investigated by flash pyrolysis-Fourier transform infrared spectrometer (FPy-FTIR). Moreover, the evolution of 8 carbonyl compounds (including formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, butanone and butyraldehyde) were analyzed by flash pyrolysis-high performance liquid chromatography (FPy-HPLC). The results showed that: 1) The pyrolyzed gas phase products mainly included water, carbon dioxide, carbon monoxide, methanol, carbonyl compounds, alkynes (mainly acetylene), alkenes (ethylene) and alkanes (methane) compounds. The increase of permeability of paper-base was beneficial to the formation of gas phase products. 2) The changes of permeability, grammage and ratio of tobacco pulp to wood pulp did not affect the formation of methane, while the increase of permeability would produce less carbon monoxide but more carbon dioxide. 3) The increase of wood pulp proportion was the main reason for carbonyl compounds and ethylene reducing. 4) Aacetaldehyde was the major carbonyl compound formed from the flash pyrolysis, followed by acetone and propionaldehyde.