Abstract: Neogene terrestrial deposits with rich fossil record are widespread in central Nei Mongol. The paucity of demonstrable superpositional sequence of assemblages and the lack of absolute dates , however, make recognition of the faunal succession and dating of the biochronology rely mainly on studies of faunal composition and evolution. The diversified faunas and new discoveries made in the last more than 20 years in this area afford an opportunity to further understand the phylogeny of mammals. The present work reviews the faunas, presents the updated faunal lists, and defines the biochronology through the analysis of the assemblages, although magnetostratigraphy is also considered when available. The faunal succession in the central Nei Mongol has assumed a prominent place in the development of a biochronology for the Neogene, covering parts of the Miocene Shanwangian , Tunggurian and Baodean, and the Pliocene Yushean of the Chinese Land Mammal Age. Informal subdivisions are suggested for Tunggurian and Baodean where it seems clearly indicated by the faunal succession. Although we are not able to propose boundary definitions for these ages, we utilize the first appearance and last occurrence of certain taxa in this region to characterize each age. Continued study of the succession , including discovery of new assemblages, will provide more data for the refinement of the biochronologic scale in this area, and for the establishment of more precise Neogene geochronologic subdivision in China.