This study examines how data on millet agriculture contribute to explaining the geographic spread of the Transeurasian languages, based on the research titled “Triangulation supports agricultural spread of the Transeurasian languages” by Martine Robbeets and colleagues. The study addresses the origins and dispersal of Transeurasian languages—such as Japanese, Korean, Tungusic, Mongolic, and Turkic—through the triangulation method, which integrates linguistic, archaeological, and genetic evidence. The central argument of the research is that the common ancestry of the Transeurasian languages can be traced back to Neolithic millet-farming communities that emerged approximately 9,000 years ago in the West Liao River Basin of Northeast China. Linguistic evidence supports this hypothesis by identifying a shared core vocabulary related to agriculture, plant cultivation, and textile production. Archaeological findings further demonstrate that millet agriculture spread gradually from this core region toward the Korean Peninsula, the Amur River Basin, and the Japanese archipelago. Ancient DNA analyses indicate that this agricultural expansion was not merely a process of cultural transmission but was also accompanied by demographic movements resulting in genetic continuity across these regions. The study argues that the early dispersal of the Transeurasian languages was largely driven by agriculture-based population expansions, while later historical periods were characterized by migrations, contact, and linguistic interaction that partially obscured this shared heritage. By foregrounding millet agriculture data, the research provides an interdisciplinary and coherent framework for understanding the geographic spread of the Transeurasian languages and contributes to broader discussions on population history and language dispersal in Eurasia.