九一八事变后，日本全面入侵我国东北地区。为了维护国家主权和领土完整，以傅斯年为代表的中国学人希望以学术研究的方式，为国家在国际联盟的调查中提供有力证据。此后“禹贡”学人也顺应时代将研究重心由地理沿革转向边疆史地。全面抗战爆发后，金毓黻著《东北通史》进一步证明东北是中国固有领土，完成“学术戍边”，产生了深远的影响。这一时期中国学者关于东北研究成果的大量涌现，体现了一代爱国学人群体的家国情怀。

After the September 18^th Incident, Japan launched an all-out invasion of Northeast China. In order to maintain the national sovereignty and territorial integrity, Chinese scholars represented by Fu Sinian hoped that academic research was able to provide strong evidence in the investigation of the League of Nations. Later, the scholars of “Yu Gong” also gradually began to adapt to the times, shifting their research from geographical change to the historical and geographical studies of the frontiers. After the outbreak of Anti-Japanese War, Jin Yufu wrote his influential General History of Northeast China, which further confirmed that Northeast China was the inherent territory of China and completed the “academic border defense”. In this period, there emerged a large number of research findings on the Northeast made by China’s patriotic scholars.