The separation of americium from lighter lanthanoids has been performedby high-speed countercurrent chromatograph (CCC) equipped with a small coiledcolumn. An extractant having higher affinity for americium, 5,8-diethyl-7-hydroxydodecan-6-oneoxime (LIX 63) was employed as a stationary phase. Americium was chromatographicallyfractionated by gradient elution from large amounts of lighter lanthanoidsthrough a coiled column.