The Goryeo dynasty was established from 935 to 1392 AD. As the country's official religion, Buddhism had enormous impact. However, Confucianism was used as the main idea for the philosophical and social structure. During the rule of Gwangjong of Goryeo (925 – 975 AD), the gwageo (과거; 科擧) examination system was strengthened due to the influences of Confucianism. The first concrete policy based on Confucianism was created during the reign of Seongjong of Goryeo (r. 981–997 AD). In 986 AD, education was expanded to the rural areas. There is a record of a policy on 1127 AD to establish a public school in each district. The public curriculum was based on books such as the Classic of Filial Piety and the Analects. There was also an annual final examination.
There were two major types of education in this period: Gwanhak (관학; 官學) and Sahak (사학; 私學). Gwanhak is defined as schools established and managed by the government. Major Gwanhak institutions include Gukjagam and Hakdang (학당; 學堂) in the cities and Hyanggyo in the rural areas. The government also established public libraries such as Bisuhwon (비서원; 秘書院) and Susuhwon (수서원; 修書院) to support educational efforts. Gukjagam was established on 992 AD as the first university in the country. It was regulated by social class and rank and played a major role in establishing future institutions.
Sahak is defined as schools not established and not controlled by the government. Major Sahak institutions include Sibido (십이도; 十二徒) and Seodang (서당; 書堂). Even though Sibido was considered a Sahak, it was controlled by the government. It was closed down on 1391 AD.