Using a historical approach based on declassified diplomatic materials, this article aims to reexamine the formation of the Sino-North Korean alliance treaty in 1961 from the Chinese perspective. The existing literature has explained the formation of the treaty mainly in the given circumstantial context or from the view of North Korea’s diplomatic initiative in the Sino-Soviet dispute. However, this article argues that the treaty was a product of China’s strategic behavior based on its national interest rather than that of Kim Ilsung’s diplomatic ability. In order to overcome the internal and external troubles, the Chinese leadership adjusted its foreign policy more pragmatically in 1960, anticipating the conclusion of the alliance treaty with North Korea. Especially after the Soviet-North Korean treaty came into view, under severe security pressure China hastened to co-opt North Korea by providing more compelling commitments in the treaty. North Korea tactfully jumped on the Chinese bandwagon. This implies that as long as North Korea has strategic value in the Chinese perspective, China would maintain its special relationship with North Korea in the context of the 1961 alliance treaty.