Abundant brachiopods have been recorded from the Middle Permian strata of Ejin Banner and its vicinities. This fauna, called Zhesi Fauna, is characterized by a mixed fauna composed of boreal cool-water elements and Tethyan warm-water elements. The brachiopod Spiriferella-Kochiproductus-Yakovlevia assemblage has been recognized from this fauna. In paleobiogeography, Ejin Banner and its vicinities were located in a transitional position between Boreal and Tethyan provinces, called Sino-Mongolia province. The geological age of Zhesi Fauna is assigned to the Roadian to Kufengian, based on an analysis of its origin, spatial distribution and associated fauna.