In this thesis we study a gradual bifurcation of the 14th century Korean celadon manufacturing industry into a dual system, caused by weakening of the unique Gangjin Jagiso (磁器所: a semi-official Celadon manufacturer) and spread of the private celadon kilns over other areas in Korea. We establish a temporal and technical relationship between the Gangjin Jagiso and the private kilns by a comprehensive examination of the overall shape and decoration pattern over a collection of large number of inlaid-celadon ceramic pieces. The collection is from twenty three private kiln sites and Gangjin sites, either newly found at the sites by the author or belonging to public and private collections. This relationship can make a valuable contribution to the study of the early Punchong ware development since those private celadon kilns spread from Gangjin Jagiso in the late Koryo Dynasty soon turned into Punchong ware manufacturers. The time period corresponding to the present study is estimated to be from 1329, the year when the Gi-Sa (己巳, name of a year in the sexagesimal cycle) inscribed (銘) inlaid-celadon was manufactured, to 1420, the latest manufacturing year of the Gong-Ahn (恭安: a temporary Koryo government office existed in 1400-1420) inscribed inlaid-celadon.*br* In the 14th century Koryo, faced with an extreme financial hardship, the royal authority pursued commercial profit-making by engaging into trade business. As a result, commercialization of the country was rapidly accelerated, allowing for a fast shift of the government-controlled manufacturing system into private businesses. This phenomenon had a profound influence on the 14th century celadon manufacturing system and quality of the celadon. Overlaid with frequent invasions of the Japanese pirates into the area, the craftsmen at the Gangjin Jagiso fled for their own private kilns in the hope for better living conditions, which led to a gradual fall of the government-controlled Gangjin Jagiso and to the manufacturing of the prestigious inlaid-celadon wares at the private kilns all over the country.*br* After a careful and systematic study, three different evolution periods were identified: the first one in 1340-1372, the second one in 1372-1392, and the third one in 1392-1420. In the first period there was a wide spread of the inlaid-celadon kilns over the country. accompanied by a noticeable drop in the quality of the celadon wares manufactured in both systems when compared to the celadon wares manufactured at Gangjin Jagiso prior to 1340. This observation is consistent with the rapid commercialization of the celadon wares and start of mass production. The Gangjin Jagiso was still the sole supplier of the celadon wares to the royal court and the government authorities. The second period was separated from the first period by the recognition of the private kilns at the equal level to the down-graded Gangjin Jagiso. The private manufactures were allowed to use a unified letter inscription Sa-Sean (司膳), name of the royal kitchen. Both systems supplied the inlaid-celadon wares to the royal court in this period. Quality of the inlaid-celadon for the royal court from both systems was even more degraded from the first period. In the third period the government-controlled Gangjin Jagiso completely disappeared, synchronized with the collapse of the Koryo Dynasty and the rise of the Choson Dynasty. The private kilns, on the contrary, flourished and changed into manufacturers of the next generation Korean ceramic wares, i.e., Punchung ware (粉靑沙器). Their locations are later listed in the 「Geography Chapter」 of Authentic Annals of the King Sejong (『世宗實錄』 「地理志」, 1424-1432).