In 1998, the Chifeng Archaeological Team excavated the fourth locality of the Dashanqian site in Harqin Banner, Inner Mongolia. They revealed deposits of the Lower and Upper Xiajiadian cultures and the Warring States period, with those of the former two cultures as the main remains. The finds of the Upper Xiajiadian culture include vestiges of earthen and stone walls built on the ground, those of semi-subterranean dwellings, a large number of pits, pottery, stone and bone objects,and small bronzes. The most interesting are the remains of circular buildings with double stone walls.Among the remains of Upper Xiajiadian culture, pits form the main part, some containing a great amount of pottery. Painted pottery vessels and small bronzes constitute the characteristic objects of this culture.The excavation clarified similarity between Localities Ⅳ and Ⅰ and provided important clues for understanding the function and nature of the fourth locality during the period of Lower and Upper Xiajiadian cultures.