Abstract: A new dinosaur, Taohelong jinchengensis gen. et sp. nov., is described based on material (a proximo-middle caudal vertebra, three dorsal ribs, an almost complete left ilium, and several armors including a partial sacral shield) from the Lower Cretaceous Hekou Group in Lanzhou-Minhe Basin, north-central China. Taohelong jinchengensis possesses three autapomorphies: neural canal of proximo-middle caudal inverted trapezium, lateral edge of preacetabular process inverted “S”-shaped in dorsal view, and sacral shield composed of various-sized and irregularly-arranged osteoderms. Cladistic analysis shows that Taohelong is a member of polacanthinenodosaurid ankylosaur, and is the sister taxon of Polacanthus foxii from the Early Cretaceous Barremian of England. Here Polacanthinae is defined as the most inclusive clade containing Polacanthus foxii Owen, 1865 but not Ankylosaurus magniventris Brown, 1908 or Panoplosaurus mirus Lambe, 1919. Taohelong represents the first occurrence of polacanthine in Asia, and indicates again the existence of a rich and unique dinosaur assemblage in the Lower Cretaceous Hekou Group in the Lanzhou-Minhe Basin.