This article examines the history of Dumolu (豆莫婁) and the formation of their consciousness of Buyeo descent through an analysis of relevant accounts in Chinese dynastic histories. The Weishu (魏書) describes Dumolu as “Old Northern Buyeo” (舊北扶餘), while the Xin Tangshu (新唐書) records that the Dumolu people identified themselves as “descendants of Northern Buyeo” (北扶餘之裔). The article argues that the account of Dumolu in the Weishu was not merely a reproduction of earlier records concerning Buyeo, but reflected certain contemporary realities of Dumolu society. It also demonstrates that Dumolu had already established diplomatic relations with Northern Wei by 485 and coexisted with the remaining Buyeo kingdom before its surrender to Goguryeo in 494. Furthermore, this article reinterprets the statement in the Xin Tangshu that “Goguryeo destroyed their state, and its people crossed the Na River.” Rather than associating this event with Goguryeo’s conquest of Eastern Buyeo, the article argues that the passage reflects the migration of groups from the Buyeo sphere during Goguryeo’s expansion into the Jilin region in the early fourth century. Dumolu thus emerged as an independent polity formed by communities that had moved north of the eastward-flowing Songhua River. The article also highlights the record that the language of Dumolu resembled those of Shiwei, Kumoxi, and Khitan. This suggests that the people of Dumolu were originally northern tribal groups that had long been incorporated into the Buyeo political sphere. Consequently, Dumolu should be understood as a polity that inherited the political traditions and cultural legacy of Buyeo despite its northern ethnic background. The Dumolu people’s consciousness of Buyeo descent was therefore not merely a political claim. It was rooted in the preservation of Buyeo traditions and historical memory, while also serving diplomatic purposes in relations with the dynasties of Central China. Ultimately, Dumolu provides an important example of how the political traditions and historical identity of a vanished polity could be reconstructed and inherited by new communities in ancient Northeast Asia.