Abstract: In the servant official system of the Eastern Palace in Han, Jin and Southern Dynasties, prince's Zhongshuzi was always the highest in rank. "Officials and Courtiers Table" in The History of the Han Dynasty has forgotten to record Zhongshuzi. During the period of Emperors Xuan, Yuan and Cheng in the Western Han Dynasty, Zhongshuzi was gradually transformed from a personal follower of the prince to an official title, a "position close to the prince" and in the same rank with "Shizhong". In the Jin Dynasty, it was clearer that Zhongshuzi was "appointed by the Court" and its power of dissuading the prince was strengthened. Managing "Fang", the "affiliated bureau" of the Eastern Palace, Zhongshuzi has three main functions and powers, that is, "following and assisting the prince, especially reminding him to deport himself in a dignified manner while receiving visitors", "pointing out the mistakes and making suggestions to the prince", and "handling state affairs and official documents". Regarding "handling state affairs and official documents", the power of Zhongshuzi was extended to have supervising authority to other officials in the Eastern Palace with its institutional classification by setting positions such as state affairs reporter in the bureau, reporting servant. During the period of the Kingdom of Song in the Southern Dynasties, it was regular that the Left and Right Guarding Generals took charge of Zhongshuzi as their additional post, revealing that the succession of the throne was attached great importance when the imperial power was once restored in the Southern Dynasties. However, during the period of the Kingdom of Liang in the Southern Dynasties, there was no specific rule about who took charge of Zhongshuzi full-timely or part-timely, showing that the independence of the position of Zhongshuzi was strengthened again. The reason was that the prince had governed the state for a long time and depended on the "documents managed by the Eastern Palace" in the late years of Emperor Wu in the Kingdom of Liang.

Key words: the Han, Jin and Southern Dynasties, Prince's Zhongshuzi , the Eastern Palace, affiliated bureau