Baekdudaegan on the Korean Peninsula is a key ecological axis in Northeast Asia that is linked to the Sihote-Alin of Russia and the Lesser Khingan Range of China. In particular, the Baekdudaegan region occupies an important geographical location where a large number of subarctic plants grow as the southernmost limit line of northern lineage plants. However, the definition of the northern lineage plants is ambiguous, and there is a limit to establishing a conservation strategy that encompasses the Northeast Asian ecological zone. Therefore, in this study, the term “northern lineage plants” of the Korean Peninsula was defined, and a list of plant species according to it was prepared. We propose the term “northern lineage plants” as plants that the southernmost limit of geographic distribution is the Korean Peninsula. The northern lineage plants were found that 616 species of 91 families. The most dominant family was Cyperaceae with 68 species, followed by Asteraceae (Compositae) with 58 species, Ranunculaceae with 41 species, and Rosaceae with 39 species.