Comparative study of acetaldehyde, furfural and 5-hydroxymethyl furfural from celluloses which differed in crystallinity was made by pyrolytic gas chromatography.Pyrolysis of tobacco cellulose at 200~300°C resulted in rapid increase in the yields of furfurals from the amorphous regions in comparison with that from the crystalline regions. At 500°C, however, acetaldehyde was obtained in higher yields from microcrystalline cellulose than that from tobacco cellulose under the same condition.In thermogravimetric analysis, the threshold temperature for the pyrolysis of tobacco cellulose was lower than that of microcrystylline cellulose. These results showed that the yields of the volatile compounds from pyrolysis of cellulose depended on temperature and crystallinity.