The present study presents fluctuations of occupational density during the Late Paleolithic in the modern day southern Korean Peninsula based on distribution of evaluated radiocarbon dates. In so doing, it attempts to explain the pattern of population fluctuation in terms of regional and super-regional interaction networks of Late Glacial and postglacial hunter-gatherers. The study proposes evaluation processes of available radiocarbon dates which provides the basis on which we can discuss the occupational history during the final Pleistocene and early Holocene. The reconstructed occupational history shows significant fluctuations: a continued increase of occupation density during the LGM is followed by notable population drops during the post-LGM and post-Pleistocene periods. The pattern is not understandable without considering the flexibility and magnitude of hunter-gatherer mobility and far-reaching social networks. Mobile hunting and gathering groups described in the ethnographic record establish and maintain large scale interaction networks in order to secure and exchange information, resources and marriage partners, which was also the case with the Late Paleolithic hunter-gatherers. Scientific analyses suggest that most obsidian artifacts in Korea originated from the Mt. Baekdu area which is about 500km away from the middle Korean Peninsula. This strong spatial ties and social networks were likely the primary factor behind the significant increase and and sudden drop of regional populations in the modern day southern Korean Peninsula during the final Pleistocene and early Holocene.