Arthur T. Pierson (1837-1911) and his former student Horace G. Underwood (1859-1916) at New Brunswick Theological Seminary collaborated for the missionary work in Korea. The aim of this paper is to provide a reconstructed perspective on their contacts with acquaintances, their cooperation, and their legacy that they have left. Underwood was introduced as a pioneer missionary in Korea in the Missionary Review of the World (MRW) to which Pierson devoted his life as a chief-editor for twenty three years. While Underwood was working as a MRW correspondent in Korea, his articles on Korea drew Pierson’s attention. Among missionaries, W. W. White’s visit to Korea in September, 1910 triggered movements of establishing a Bible school in Seoul. The Union Bible School managed by Presbyterians and Methodists was an outcome from the movements although it did not come with permanent buildings. A.T. Pierson has made a great contribution to missionary work in Korea. His friends who respected and admired him in the world conveyed out a plan for a memorial of his devoted life and spirit after A.T. Pierson’s sudden death in New York in June 3, 1911. He passed away after a short six-month stay in Korea. There were two prominent leaders involved in the establishment of a memorial, which was called Arthur T. Pierson Memorial Bible School in Seoul, Korea: his eldest son D. L. Pierson in New York and Underwood in Seoul. This paper is about the historical background, process and meaning of Underwood’s involvement in it.