Two new protoceratopsid specimens excavated from the Late Cretaceous Wulansuhai Formation at Bayan Tal near the town of Alaten Obo, Alxa Right Banner, Alxa League, western Inner Mongolia can be further included within Protoceratops hellenikorhinus based on their features such as: skull total length more than 700 mm, ventral edge of the dentary nearly straight, horizontal ridge on the maxillary lateral side relatively straight and reduced, and premaxillary teeth absent. Here the diagnosis of this species is revised as follows: largesized species of the genus Protoceratops with skull total length exceeding 700 mm in adult, dorsally prominent nasal horns, lack of premaxillary teeth, straight and strongly reduced rostrocaudal ridge on the lateral side of maxilla, long projection of the squamosal contacting the quadratojugal, straight ventral edge of dentary, evident angle between the anterior and ventral edges of predentary, and caudal edge of the angular formed by a caudally facing triangular surface. The new specimens are the first occurrence of Protoceratops hellenikorhinus from Alxa region, western Inner Mongolia, showing Bayan Tal, Alxa Right Banner to represent the second area yielding this species following Bayan Mandahu, Urad Rear Banner. The new discovery expands the geographical distribution of this taxon, and provides the crucial information for the correlation of dinosaur faunas between the two areas.