Confucianism, Taoism and Buddhism are often considered the major religions in Korea. Among them, Buddhism impacted Korea in various ways, such as art, architecture, folk ethics, and political structure between the 6th century, when Buddhism was introduced to the Silla Kingdom , and the 14th century, which marks the end of the Koryŏ dynasty. This essay will demonstrate the impact of Buddhism on the progress of building the political structure and its importance. The first introduction of Buddhism took place in the fourth century, during the Three Kingdoms period. Koguryŏ was the first of the Three Kingdoms to officially adopt Buddhism during the second year of King Sosurim's reign (372). The king maintained friendly relations with ancient Ch'in in northern China. Fu Chien, the powerful ruler of ancient Ch'in, who supported Buddhism, sent a monk named Sundo with images and a cannon of Buddha to Koguryŏ. That year, King Sosurim accepted Buddhism. In the case of Paekche, Buddhism was introduced by a monk from Eastern Chin of southern China during the first year of King Ch'imnyu's reign (392). Soon after Buddhism came to Paekche, King Asin proclaimed that people should believe in Buddhism and pursue happiness (392). Buddhism had only a fundamental level of doctrine in Ch'in where Buddhism spread to Koguryŏ and Paekche. Thus, Buddhism was not deeply understood in these two countries either. Therefore, although Buddhism was adopted very early in these two countries, Buddhism could not have a deep impact on Koguryŏ and Paekche on their political structures. Although the official endorsement of Buddhism in Silla was the last among the Three Kingdoms, its implementation was the most successful in society. In fact the unofficial arrival of Bu...... middle of paper ......hical, focused solely on the accumulation of wealth and power. This resulted in an oversized Buddhist establishment which resulted in over-the-top, completely unnecessary monastery building. Thus Buddhist monasteries influenced the whole country. This decadence was one of the factors in the fall of Koryŏ. This essay demonstrated the enormous impact of Buddhism on Silla and Koryŏ society. Silla became the most powerful kingdom among the Three Kingdoms through reform based on Buddhism and achieved the unification of the Korean Peninsula. The Koryŏ dynasty maintained the Hoguk Pulgyo which was the Buddhist ideology in order to protect its territory from foreign invasions. Considering these points, it can be said that there was a close connection between Buddhism and the political structure from the 6th to 14th centuries on the Korean Peninsula..