At the end of the Eastern Han Dynasty, Cao Cao transformed Shangshutai into a central government agency. In addition, he also took his cronies and aides as secretaries, and sent secretaries Zuo Cheng and You Cheng to take charge of sending and receiving documents, drafting and issuing orders, in order to replace the former Shangshutai and form a new central secretariat organ. After Cao Pi proclaimed himself emperor and built Wei, he changed the order of the secretariat to the order of the secretary, added the post of supervisor of the secretariat, set up the province of the secretariat, was responsible for drafting imperial edicts, was in charge of the memorial, and became the central secretariat of the new dynasty.

During the Wei, Jin, Southern and Northern Dynasties, the authority of Zhongshu Province expanded again, from the initial "praising imperial edicts, remembering current events and writing articles" to participating in secrets, handling government affairs and taking charge of 265,438+0 affairs, and its staff also soared, with one or two hundred people copying books and writing documents alone. For this reason, the rulers added Xiamen Province and Shangshu Province respectively, in order to disperse the power of Zhongshu Province, so that the three provinces each bear a part of the Central Secretariat, which makes them cooperate with each other and restrict each other.