This study was carried out to determine the differences of essential oil components among Korean, Chinese and Japanese red ginseng, and Korean white ginseng (Panax ginseng C.A Mayer) , American and Canadian ginseng (P. Quinquefolium), and sanchi ginseng (P notoginseng). The steam distilled oils of these ginsengs were analyzed by GC and GC-MS, and 22 sesquiterpenes, 8 sesquiterpene alcohols, 8 monoterpenes, 5 aldehydes, 4 esters, 3 acids, 2 alcohols and 5 miscellaneous components were identified. The major oil components of Korean, Chinese and Japanese red ginseng were $eta$-panasinsene, $eta$-caryophyllene, $alpha$-panasinsene, $alpha$-neoclovene, selina-4,11-diane, bicyclo-ger-macrene and spathulenol. The contents of $eta$-panasinsene, $alpha$-neoclovene, $alpha$-basabolene and spathulenol were higher in Korean red ginseng than Chinese and Japanese red ginseng. The contents of $alpha$-cubebene, selina-4,11-diene and ledol were higher in Chinese red ginseng than Korean and Japanese red ginseng, but those of selina-4,11-diene and spathulenol were lower in Japanese red ginseng than Korean or Chinese red ginseng. On the other hand, the GC patterns of the oils from American, Canadian and sanchi ginseng were different from that of Korean white ginseng.