The Three Departments and Six Ministries system was the main central administrative structure adopted in Imperial China. While its separate departments first took shape during the Han dynasty (206 BCE – 220 CE), it emerged in a more complete form during the Sui dynasty (581–618 CE), and was adopted in some form by all Chinese dynasties since.
The Three Departments were the top-level offices of the administration. They were the Central Secretariat (中書省; 中书省; zhōng shū shěng), the Chancellery (門下省; 门下省; mén xià shěng), and the Department of State Affairs (尚書省; 尚书省; shàng shū shěng). They were the principal divisions of a differentiated set of secretarial functions, distributed among the three departments. The head of the Central Secretariat or the Department of State Affairs was generally referred to as the Chancellor, next only to the Emperor in rank and power.
The Six Ministries, also traditionally translated as "Boards", were direct administrative organs of the state, and each was headed by a Minister/Secretary (尚書; 尚书; shàng shū) who was assisted by two Vice Ministers/Secretaries (侍郎; shì láng).
Before the institution of the Three Departments and Six Ministries, the central administrative structure of the Qin and Han dynasties was the Three Lords and Nine Ministers (三公九卿; sān gōng jiǔ qīng) system. Nonetheless, even then, offices which fulfilled the same functions as the later three departments were already in existence.
The Department of State Affairs was first devised during the Qin dynasty (221–206 BCE), originally in an archival role. During the reign of Emperor Wu in the Western Han dynasty (206 BCE – 9 CE), the Secretariat's office was also instituted, as a channel of communications between the Emperor's advisors and the government as a whole. By the Eastern Han dynasty (25–220 CE), an office of advisors and reviewers had also been set up.
By the time of the Cao Wei state (220–265 CE), the emperor Cao Pi made use of this base of advisers to officially institute the Secretariat to balance against the powerful Department of State Affairs. This was the first office known as the 'Secretariat' to fulfil functions similar to its later form, drafting imperial edicts.
The office of the Chancellery, as a review mechanism, was first instituted during the Jin dynasty (265–420 CE) and carried on throughout the Northern and Southern Dynasties period (420–589 CE), where it often became the most powerful office in the central government.
The Central Secretariat (中書省; 中书省; zhōng shū shěng) or simply the Secretariat was the main policy-formulating agency that was responsible for proposing and drafting all imperial decrees, but its actual function varied at different times. Under the Song dynasty (960–1279), as well as under the Liao (907–1125) and Jin (1115–1234) dynasties, these organs exercised much of the executive authority of the emperor. Under the Yuan dynasty (1271–1368), the Central Secretariat with enlarged functions stood alone as the sole organ to lead the civil administration in the Yuan realm. This structure was adopted by the early Ming dynasty (1368–1644), but it was abolished after the Hongwu Emperor executed the chancellor Hu Weiyong. The Central Secretariat was discontinued by later rulers.
The Department of State Affairs (尚書省; 尚书省; shàng shū shěng) controlled the six ministries since the Sui dynasty (581–618 CE) and was the highest executive institution of the imperial government. During the Yuan dynasty, however, the Central Secretariat replaced the Department of State Affairs as the top government agency. In fact, the Department of State Affairs was only occasionally established to handle financial affairs under the Yuan dynasty, such as during the "New Deals" of Emperor Wuzong. This department was never set up again after the Yuan dynasty.
The Chancellery (門下省; 门下省; mén xià shěng) was one of the three departments, whose function was to advise the Emperor and the Central Secretariat, and to review edicts and commands. As the least important of the three departments, it was discontinued after the Song dynasty. After Hu Weiyong's incident in the early Ming dynasty, the Three Departments and Six Ministries structure was formally replaced by the Six Ministries structure.
The Ministry of Personnel or Board of Civil Appointments (吏部; lì bù) was in charge of appointments, merit ratings, promotions, and demotions of officials, as well as granting of honorific titles.
The Ministry of Revenue or Board of Revenue (戶部; 户部; hù bù) was in charge of gathering census data, collecting taxes and handling state revenues, while there were two offices of currency that were subordinate to it.
The Ministry of Rites or Board of Rites (禮部; 礼部; lǐ bù) was in charge of state ceremonies, rituals and sacrifices; it also oversaw registers for Buddhist and Daoist priesthoods and even the reception of envoys from tributary states; it also had a function of diplomacy when dealing with foreign affairs before Zongli Yamen was established in 1861. It also managed the imperial examinations.
The Ministry of Defence or Board of War (兵部; bīng bù) was in charge of the appointments, promotions and demotions of military officers, the maintenance of military installations, equipment and weapons, as well as the courier system. In times of war, high-ranking officials in the Ministry of Defence also served as strategists and advisers to the frontline commanders. Sometimes, they even served as frontline commanders themselves.
The Ministry of Justice or Board of Punishments (刑部; xíng bù) was in charge of judicial and penal processes, but had no supervisory role over the Censorate or the Grand Court of Revision.
The Ministry of Works or Board of Works (工部; gōng bù) was in charge of government construction projects, hiring of artisans and laborers for temporary service, manufacturing government equipment, the maintenance of roads and canals, standardisation of weights and measures, and the gathering of resources from the countryside.
Beneath each Ministry were many Bureaus (司; sī), bodies responsible for grassroots administration.
Aside from the "Three Departments", there were three others equal in status to them, but they are rarely involved in the administration of the state.
The Department of the Palace (殿中省; diàn zhōng shěng) was responsible for the upkeep of the imperial household and the palace grounds.
The Department of Secret Books (秘書省; 秘书省; mì shū shěng) was responsible for keeping books about astronomy and astrology.
The Department of Service (內侍省; nèi shì shěng) was responsible for staffing the palace with eunuchs.
