To clarify the variation in the pharmacologically active components of the essential oil contained in the rhizomes of Atractylodes lancea and A. chinensis growing in China, we transplanted the rhizomes of the wild plants from 18 populations, including A. koreana, in the same experimental field. After two or three years' cultivation, main essential oil components, i.e., the sesquiterpenes: elemol (1), atractylon (2), hinesol (3), beta-eudesmol (4), selina-4(14),7(11)-dien-8-one (5), and the polyacetylene of atractylodin (6) were determined by capillary gas chromatography. The analytical data of 306 cultivated plants were compared with plants collected in their habitat. A. lancea varied significantly in the contents of the components after cultivation; however, the correlation coefficient in the contents of 3, 4, and 6 between the wild and cultivated plants were 0.985, 0.954, and 0.945, respectively (p < 0.001). Compared to this, A. chinensis had constant content values. Three types of A. lancea and two types of A. chinensis, which are distinguished by the characteristics of the components in the wild conditions, were statistically recognized after cultivation. From these results, it was determined that the geographical variation in the components of these species mainly reflects genetic variability.