We describe fossil specimens of two taxa of anthracotheriid artiodactyls (Mammalia) discovered in the upper Eocene Ergilin Dzo Formation of southeastern Mongolia and briefly review the late Eocene anthracotheriids of northern East Asia. The specimens described here are: (1) an upper molar, an astragalus, and a calcaneum of a small bunodont anthracotheriid; and (2) upper and lower postcanine dentitions, an astragalus, and a distal tibia of a Bothriodon/Aepinacodon-like selenodont anthracotheriid. This paper provides the first description and figures of the Anthracotheriidae from the formation, which were hitherto poorly understood. The anthracotheriid fauna of the formation currently consists of two species, an indeterminate bunodont anthracotheriid and cf. Bothriodon sp. This is the first discovery of a bunodont anthracotheriid in the late Eocene of the northern part of East Asia. The anthracotheriids are mainly represented by selenodont and bunoselenodont species and are rare faunal elements in the late Eocene of northern East Asia; in contrast, they are mainly represented by bunodont and bunoselenodont species and are predominant faunal elements in the late Eocene of southern East Asia. This implies a paleobiogeographical separation between the northern and the southern parts of East Asia during the late Eocene.