The chronology of thirteenth and fourteenth century Lung-ch'uan ware has long relied on rough approximations no more specific than "Southern Sung to Yuan," or "Sung/Yuan." The present essay will, on the basis of celadons excavated in China and Japan, attempt to establish more precise standards for dating Yuan dynasty Lung-ch'uan ceramics. The period. in question extends from the first development of high quality "thin body, thick glaze" celadon in the Southern Sung to the fully fledged Lung-ch'uan ware of the Yuan. It can be divided into four phases: Late Southern Sung, End of Southern Sung to Early Yuan, Mid-Yuan, and Late Yuan to Early Ming. The paper provides an in-depth discussion of the glaze color, crafting techniques, and decorative characteristics of each period, thereby establishing a clear visual basis for future discussions of Yuan Lung-ch'uan chronology.