The composition of volatile components in 18 Citrus Archicitrus species, 17 Citrus Metacitrus species and two Fortunella species, according to the classification system established by Tanaka, was investigated using headspace gas chromatography-mass spectrometry. The composition of 48 volatile compounds in the juice of these species was determined, and principal component analysis was performed. Scores for the 1st and 2nd principal components are plotted as a scatter diagram. In Citrus Archicitrus, samples of Citrophorum, Cephacitrus and Aurantium formed individual groups, but others did not. In Citrus Metacitrus, samples of Acrumen were divided into two different groups. The composition of volatile components in citrus juice was consistent with each grouping of Tanaka's system, in particular, in the case of dividing the Citrus genus into the two subgenera Archicitrus and Metacitrus.
