Abstract: Renewed interest in the early history of cricetids has developed within the past 15 years, but there is little evidence to support these studies. The systematic position of Simimys from the upper Eocene of North America has long been unsettled. Cricetodon schaubi, a unique Eocene cricetid definite, wag described by Zdansky (1930) only on the basis of -two lower molars. In that case, it is necessary to do further field work for discovery of new material. Fortunately, about two hundred isolated teeth assignable to a new genus were gathered in the Middle-Late Eocene deposits of the Yuanqu Basin by means of screenwashing recently. It seems that the new genus has a close relationship with the known Oligocene cricetids.