The current study aims to investigate Paeche`s Buddhism in King Bup`s reign. The name of King Bup needs to be analysed in the aspect of Buddhism rather than that of Confucianism because the filial duty emphasized by the followers of King Sung were all related to Buddhism Moreover, this was closely related to political movements of the lineage of King Sung agglomerated to strength the throne. It is difficult to relate the construction of the Ohap temple to King Bup`s coronation. The political position of would-be-king Hye during the reigns of King Widuck exerted great political power. The sovereign power of King Widuck was exercised with the corporation of Hye. In order to keep uniting the lineage of King Sung firmly, they needed King Hye to inherit the throne. After King Hye, King Bup who accumulated considerable political power, inherited the throne instead of King Widuck`s son, Aja. The lineage of King Sung required to build other national Buddhist temples to compete with the Neungsnari temple(능산리 사원). But the real purpose was to launch the reorganization of the country by establishing national temples in three mountains and five peaks(3산 5악). This plan was launched in full scale by King Bup and the outcomes were the Kumsan temple and the Ohap temple. These establishment of temples reflected the dissemination of Buddhism to provinces. The constant construction of national temples by King Bup reflected that the Paekche`s Buddhism revealed of the characteristics of national Buddhism. As for Paekche`s Buddhismhowever, it was closely related not only to Kaeuljong(계율종) but also to Bupwha faith(법화신앙). This Bupwha faith seemed to gain more importance after the reign of King Widuck, which implies that it was closely related to beef up political power of King Sung`s lineage. The construction of the Wangheung temple could be viewed as the crucial step for King Bup`s power. It needs further to investigate other reasons of King Bup`s death rather than assuming the confrontation of the royal power and the noble power. This assuming denied the father-son relationship between King Bup and King Mu. But the fact that King Mu finished the construction of the Wangheung temple implies that he achieved King Bup`s political goal. King Mu`s other political activities also showed the establishment of sovereignty.