After the reluctant opening of ports, the Chosen State carried out radical administrative change for its modernization and independence. This paper inquires into the changes of sacrificial rites in the process of establishing modern government from the Kab-o Reforms(甲午改革) to the period under the rule of the Japanese Residency-General(Tonggambu, 統監府) in Korea. At the 1894 Kob-o Reforms Royal affairs were excluded from the administration of state and were attached to the Department of the Royal Household(Kungnaebu, 宮內府). The affairs of sacrificial rites belonged to the Department of Royal Household, so sacrificial rites were strongly associated with the Royal Family. Also magical rites, common customs, and tributes to for the Chinese were reduced in the Kap-o Reforms. But, during period of the Kwang-mu reform(光武改革), the sacrificial rites that had been abolished in former times were restored. And the establishment of the Great Han Empire(Taehan Cheguk, 大韓帝國) brought new sacrificial rites that represented the new Empire. First, the Sacrifice to Heaven(Hwanguje, ?丘祭) at the Round Altar(Hwangudam, ?丘壇), which was rebuilt 1897, became the central symbol of the independent nation, which was based on the Confucianism. Subsequently the Southern Altar(Namdan, 南壇) for the Gods of Wind, Cloud, Thunder, and Rain, was changed to the Altar for the Gods of Mountains and Rivers(Sanchendan, 山川壇). And the Rite of Praying for Grain(Kigokje, 祈穀祭), which had been carried out at the Alter of State(Sajikdan, 社稷壇), was moved to the Round Altar. The most important change was found in the rituals for royal ancestors in the period of the Kwangmu-reforms. In 1899 the graves of primogenitors that had not had services at the Royal Temple(Chongmu, 宗廟) were made sacred, and their rites check meaning were accommodated to the State Register of Sacrifices(Sajen, 祀典). Also, the Empire Kojong presented the titles of emperor to five kings-T'aejo(太祖), Changjo(莊祖), Chongjo(正祖), Sunjo(純祖), and Ikjong(翼宗)- posthumously. Also He rebuilt the Halls of Royal Portrait(Jinjen, 眞殿), Sunwonjen(璿源殿), Mokchenjen(穆淸殿), and Youngheejen(永禧殿). These can be interpreted as solidifing royal authority as being the Great Family(Daejongga, 大宗家). But, the most of rituals of state were reduced and abolished under the rule of the Japanese Residency-General(Tonggambu, 統監府) in Korea. The Japanese Residency-General divided the sacrifices of state to the National rituals(Kugsa, 國祀) and the Royal ritual(Jesilsa, 帝室祀) to depress the authority of Emperor. These changes in rituals from 1894 to 1908 can be characterized as follows: First, the reforms of the sacrificial rites of state could develop not to antagonize all rites of sacrifice or gods, but to abolish the parts of sacrifices that were regarded as useless. It means that modernization needed the rites of sacrifices. But, most of the rituals that survived modernization belonged to the Royal family. Secondly, the sacrificial rites of state had been treated in connection with the Royal Family. The common customs of rituals(Sokre, 俗禮) become issue in three periods because these were carried out by the royal family. From a religious point of view, the main issues were whether the rituals of the Royal family were to be included in the formal system or not. In the latter period of the Chosen dynasty King Sukjong, YoungJo, and Chongjo had raised the authority of the Royal family by publishing Sonwon-Kyebo-kiryak(璿源系譜記略), building Chokyungmyo(肇慶廟), and erecting monuments for the late kings. Emperor Kojong succeed these king's tasks. But, it represented the atmosphere of contemporary society. The excess of Sewon(書院) and the strengthening of the whole clan split the public system called Sajok(士族). These changes can be called 'the popularization of families' or 'the making the family private'. In modern Korea it was the important task to bring these families into the modern system. The transformation of the rituals of state represented this contemporary social situation.