The peripheral Mongolic languages of the Qinghai-Gansu area in China comprise Eastern Yugur (Shira Yugur) and the Shirongol languages. The latter can be subdivided in a Monguor branch, consisting of Mongghul and Mangghuer, and a Baoanic branch, consisting of Baoan, Kangjia, and Dongxiang (Santa).

The internal taxonomy of the Qinghai-Gansu languages will be discussed in a separate section. The Qinghai-Gansu languages are increasingly well- described. They have also been the subject of studies in language contact, mostly in the context of the Amdo or Qinghai-Gansu Sprachbund. This study will approach the phonology of Qinghai-Gansu Mongolic from a comparative historical viewpoint. It provides an overview of the phonological developments of the Qinghai-Gansu languages, comparing them to the reconstructed ancestral language. At the same time it will investigate the archaic features that can be found in these languages, in order to improve the reconstructions of individual Mongolic lexemes. The book ends with a comparative supplement of about 1350 reconstructed Common Mongolic items, accompanied by the modern forms they are based on and, where necessary, arguments for the chosen reconstruction.