AbstractA sample of pyrolytic oil of Vietnamese origin, extracted from Cupressus funbris Endl. was investigated by GC‐RI, GC‐MS and 13C‐NMR spectroscopy. In the pyrolytic oil, dominated by sesquiterpenes (76% of the total composition), 46 components were identified after repeated silica gel chromatography. The main components were: α‐cedrene (26.7%), cedrol (12.3%) and β‐cedrene (6.6%). The pyrolytic oil differed from the commercial Chinese cedarwood oil (C. funebris wood oil), on the one hand by the absence of thujopsene and conversely the presence of several bicyclo[4.4.0]decane hydrocarbons and alcohols (selinane and cadinane derivatives), and on the other hand by the presence, as minor components, of phenol derivatives. The composition of the pyrolytic oil was compared with that of a commercial sample of cerdarwood oil [53 components identified, thujopsene (25.9%), α‐cedrene (24.1%), cedrol (11.3%) and β‐cedrene (7.4%)]. Copyright © 2006 John Wiley & Sons, Ltd.