The article outlines the fi ndings of excavations of a ritual building discovered at the Southern Ussuri fortifi ed site (Primorye Territory), identifi ed as the capital of the Xupin county of the Jurchen Jin Dynasty. Previously it was thought that the Southern Ussuri town was founded by the Balhae people and that during its early period it was the center of the Balhae district of Shuaibin, while the Jurchens appeared there later. However, our fi ndings suggest that the town belonged to the Jurchens from the beginning. Despite the high density of modern buildings on the territory of the medieval town, our study of what was left of the habitation deposits has allowed us to determine the architectural horizons and to associate them with specifi c historical periods. Based on the analysis of materials excavated from a building located on the upper architectural horizon, architectural features of a medieval building representing the Buddhist tradition were described: the colonnade, roof style, and sculptural representations of dragons, phoenixes, and Buddhist immortals. New decorative motifs on the tiles of the front and eaves of the roof were discovered, and new standards of building materials were identifi ed. The fi ndings suggest that the ritual structure dates to the 13th century— the second period of the Jurchen Eastern Xia State (1234–1276), preceding the Yuan Dynasty. Special architectural features revealed during the excavations of the upper architectural horizon are reliable indicators for assessing the age of other sites in Primorye.