Promimomys asiaticus sp. nov., the first known species of the genus in East Asia, is described. The material was collected from the early Pliocene cave deposit in Dajushan Hill, Huainan, Anhui Province. Promimomys was first found in Europe and considered as the ancestor of the family Arvicolidae. The new species from China is distinct from the type species, P. cor, and other known species in its thicker enamel of uniform thickness, simple anterior loop of m1, and blunt, salient angles. It is more primitive than other known species in Europe and North America and also more primitive than Mimomys bilikeensis of early Pliocene of Inner Mongolia. It is thus the earliest and the most primitive arvicolid rodent known. The discovery of Promimomys asiaticus sp. nov. is significant to the study on the origin and the phylogeny of arvicolids, and to the discussion of the intercontinental dispersal events of arvicolids.