The Sanjiangyuan region of Qinghai-Tibetan Plateau is recognized as a biodiversity hotspot of alpine mammals but a barren area in terms of amphibians and reptiles. Here, we describe a new pit viper species, Gloydius rubromaculatus sp. n. Shi, Li and Liu, 2017 that was discovered in this region, with a brief taxonomic revision of the genus Gloydius . The new species can be distinguished from the other congeneric species by the following characteristics: cardinal crossbands on the back, indistinct canthus rostralis, glossy dorsal scales, colubrid-like oval head shape, irregular small black spots on the head scales, black eyes and high altitude distribution (3300-4770 m above sea level). The mitochondrial phylogenetic reconstruction supported the validity of the new species and furthermore reaffirms that G. intermedius changdaoensis , G. halys cognatus , G. h. caraganus and G. h. stejnegeri should be elevated as full species. Gloydius rubromaculatus sp. n. was found to be insectivorous: preying on moths (Lepidoptera, Noctuidae, Sideridis sp.) in the wild. This unusual diet may be one of the key factors to the survival of this species in such a harsh alpine environment.