Abstract: A partial skeleton is described from the Upper Cretaceous Iren Dabasu Formation of Nei Mongol that represents a new therizinosauroid theropod, Erliansaurus bellamanus gen. et sp. nov. Distinctive characteristics of the new species include enlarged nutritional foramen on anterior caudals, prominent crest-like posterior trochanter on the humerus bordered medially by an oval depression, rugose swelling located dorsal to the ischiadic peduncle on the lateral surface of the ilium, posterior margin significantly higher than anterior margin on the fibular proximal end, and distally located hypertrophied anterior trochanter on the fibula. Preliminary analysis suggests that E. bellamanus represents an intermediate taxon between the primitive therizinosauroids and the advanced Therizinosauroidae. The discovery of E. bellamanus provides important information regarding the diversity within Therizinosauroidea.