Yun Ch'iho (1864–1945)'s voluminous personal letters and diaries have placed him at the center of a diverse array of historical studies on modern Korean history. Yun's diaries can be especially helpful in revealing important aspects of a Christian publishing company called Ch'angmunsa, which began operations in January 1923. Yun's diary entries yield insights into not only the complexities of the colonial publishing market, but also the entangled history of Korean Christianity during the cultural rule period of the 1920s. The establishment of Ch'angmunsa was part of a broader movement among Korean Christians to achieve more cultural autonomy from the Western missionaries. Korean Christian leaders maintained close relations with the missionaries who spread Christianity in Korea, but they also sought to establish their own basis for Christian cultural production. Through a close reading of Yun's diary, we can gain a better understanding of the challenges of Christian publishing, the complexities of the Christian Nationalist movement, and the tensions between the missionaries and the Korean Christian leadership in colonial Korea.