The 21st Century Hymnal as an amendment and addition to the United Hymnal(1983) was published by Korean Hymnal Society in 2006. Now is widely used in most Korean protestant churches. The addition was done in two sides. First, the hymns of korean writers and of the various nations were added, as described in the preface of the hymn book. Second, supplemented were worship hymns, psalm hymns, hymns for the church events, and hymns for young generations. While originally, it was planned to be published in 2000, the publication lasted 6 more years. It took longer to persuade the churches of the need of the new hymnal, and the contract conflict between the Korean Hymnal Society and the press companies made it even longer. The conflict has not be resolved even until now, 7 years after the publication. No one knows whether the 21st Century Hymnal will have the same influence as the United Hymnal had, which had been used by all the Korean protestant churches. In this article, first, I will try to describe how the edition was done, including the situation and progress. Then, I will show how it is different from the United Hymnal. Also, I will explore, how well the purposes of edition were accomplished. I hope this paper would be a contribution to the study of korean Hymnology.