Abstract: A new species of the crown-antlered deer, Stephanocemas guangheensis sp. nov. is described based on an adult antler, three cheek teeth, an astragalus, and a calcaneum. These specimens were discovered from the early Middle Miocene Dongxiang Formation of the Linxia Basin in Gansu Province, northwestern China. S. guangheensis is a small-sized crown-antlered deer, and its antler is broadly palmate, with six tines in the adult. It combines characters different from other species of the genus Stephanocemas, such as a moderately large palm, and superiorly orientated lateral tines. Its palmar base is a short semicircular column with a straight lateral margin and a shedding scar. This unclosed shedding scar is a shallow depression with dense spongy pores. S. guangheensis is more derived than S. aralensis and S. actauensis of the late Early Miocene, but more primitive than S. palmatus of the Middle Miocene. In the Linxia Basin, the Dongxiang Formation is poorly fossiliferous, so the discovery of S. guangheensis provides new evidence for the age estimation of this formation.