That Koryo Dynasty celadon represents a peak of aesthetic achievement was recognized as early as the twelfth century by the Chinese. From the beginning of the current century, Korean celadon has been a focus of Japanese and Western connoisseurship. More recently, the publication and exhibition of ceramics excavated in Korea have brought some of the finest celadons to the attention of Westerners. It is the reconstruction of the technology underlying manufacture of these celadons and the investigation of its relation to Chinese practice that are the subjects of this essay.