Since the 17th century, the rulers of the Qing Dynasty, influenced by the closing-off policy and the Qing-Chǒsn tributary relationship, have preserved a large area of forested land between the Willow Side and the Yalu River. One of the purposes of preserving the forest area was to maintain a buffer zone by isolating the residents on both sides of the Yalu River, thus demonstrating the Qing emperor's benevolence. However, in the late 19th century, Northeast China became the site of global rivalries and competition. Under pressure from Tsarist Russia and plagued by internal famine, the Qing government resorted to a series of new policies to encourage immigration and open the Yalu River forest for commercial logging. Meanwhile, to deal with the Malthusian trap in Japan, it regarded the Korean Peninsula and the northeast of the Qing Dynasty as expansion targets. Japan's victories in the Sino-Japanese War (1894-1895) and the Russo-Japanese War (1904-1905) consolidated its position in Northeast Asia and paved the way for its military control and resource management in the forests of the Yalu River. With the establishment of the Sino-Japanese Yalu River Logging Company in 1908, Japan took control of forestry development on the Sino-Korean border. This paper focuses on the relationship between forest development and frontier formation. It attempts to re-examine the process of modernization of the northeast frontier from a forest perspective, discussing how forest-related commerce, negotiation, and conflict have been internalized into labor disputes and thus reshapes the history of forest boundaries.