The Pyrolytic behavior of glycyrrhizic acid and glycyrrhetini c acid, which are natural flavorants for manufactured cigarettes was observed to find its contribution to the smoke composition. Pyrolyzates of them at 800t were identified using a gas chromatography and a mass spectrometer. According to the analysis of the pyrolytic Products, 43 different compounds were identified Among them the aromatic hydrocarbon compounds were found to be the major products.