The neutral volatile oil of the flower stalk of Petasites japonicus was separated by silica gel column chromatography and then by gas chromatography. Isopentanol, 3-hexen-1-ol, 1-nonen-3-ol, l-linalool, and veratrole were identified as the minor constituents. The volatile oils of the flower stalk collected from various places in Japan and oils extracted from various organs of the plant were examined (Table I). Large quantities of 1-nonene and angelic acid were found in any parts of the plant. The oil obtained from flower stalks consisted mainly of 1-undecene, 1-tridecene, 3-acetoxy-1-nonene, β-elemene, and β-bisabolene, and the oil from the leaves consisted mainly of 1-tridedene, β-caryophyllene, and alcohols.