A new ankylosaur (Tianzhenosaurus youngi gen. et sp. nov.) is described based on the specimens from the Upper Cretaceous Huiquanpu Formation, Tianzhen County, Shanxi Province. Morphologically it is similar to Saichania chulsanensis from the Upper Cretaceous Barun Goyot Formation in the Nemegt Basin, Mongolian Gobi Desert, but different from the latter in smaller and isosceles triangular skull, longer premaxilla, nearly parallel maxillary tooth rows with slightly narrower posterior width than snout width, and vertical posttemporal region with a narrow and vertically expanded occipital condyle. The new discovery significantly enriched the ankylosaur fossil record in China, and has an important bearing on understanding the evolution, migration, and geographical distribution of the Late Cretaceous ankylosaurids.