Abstract: EI Youzhong was a prominent statesman of the first three reigns of the Northern Song Dynasty and was known as one who agilely planned majors events. He held numerous official positions throughout his life, and wherever he went, he implemented good governance. His appointments ranged from low-ranking officials to the position of provision commissioner of Northern Palace. His ranking titles was as high as a Chief Censor plus a Grand Guardian title. The verification and description of LEI’s official career can enhance our understanding of the appointment system of the Northern Song Dynasty, and this study also provides a clear understanding of the complex historical situation of the first three reigns of the Northern Song Dynasty.