CAI Jing was appointed the prime minister in the Chongning period of Song Hui-tsung. The Medical School was moved to the Imperial College from Taichang Temple. It used a 3-year education system and divided graduates into three grades. The preferential policies promised top students as 8 or 9-rank official position, which attracted a lot of intellectuals into the field of medicine. CAI Jing was demoted three times respectively in the fifth year of the Chongning period, the third year of the Daguan period and the second year of the Zhenghe period, and was promoted again after each demotion. Influenced by changes of CAI Jing's position and relative policies, the Medical School was also established and abolished three times.