The volatile constituents of Castanopsis flower (C. caspidata Schottky var. Sieboldii Nakai), which had not been studied prior to this report, have been investigated by gas chromatography-mass spectrometry. Fifty-six compounds were identified in the oil which was obtained from this flower by the distillation-extraction method (Likens and Nickerson apparatus). The compounds reported here were 11 monoterpenes, 4 sesquiterpenes, 21 aliphatic compounds, 12 aromatic compounds, and 7 heterocyclic compounds. Major compounds of this oil were salicylaldehyde, o-aminoacetophenone, methyl salicylate, linalool, and nonanal.