The governmental structure that the Three Kingdoms 三國 (220-280), the Jin 晉 (265-420), and the Southern 南朝 (420~589) and Northern Dynasties 北朝 (386-581) inherited from the Han empire 漢 (206 BCE-220 CE) was maintained by most regimes as a façade behind which a succession of military rulers governed with personal aides and relatives whose status was gradually regularized into a stable new structure with semi-independent regional states (princedoms). Every regime during the era of division had distinctive characteristics in its governmental structure, especially the Non-Chinese Sixteen Kingdoms 十六國 (300~430) and the Northern Dynasties that developed their original native or non-Chinese organizations that, through several phases, became more similar to the Han-Jin traditions. Many ad-hoc administrative structures and official titles proliferated during that phase.
The central government of the Western Jin 西晉 (265-316) and the northern regimes used the old capitals of Luoyang 洛陽 (modern Luoyang, Henan) and Chang'an 長安 (modern Xi'an 西安, Shaanxi) as their seat of government, while the Southern Dynasties made use of the capital of the empire of Wu 吳 (222-280), Jiankang 建康 (modern Nanjing 南京, Jiangsu). While the imperial princes in the Wei empire 曹魏 (220-265, the "righteous" successor of the Han dynasty) in the north were required to take up residence in their territorial bases, the Jin dynasty allowed princes to hold important posts in the central government.
The highest posts or titles of the Jin central government were inherited from the Han, like the triumvirate of the Three Dukes (sangong 三公: Counsellor-in-chief chengxiang 丞相, Defender-in-chief taiwei 太尉, and Grand Preceptor taishi 太師 or taizai 太宰). This trinity was later expanded to the so-called Eight Dukes (bagong 八公), a group that included the Grand Preceptor, Grand Mentor (taifu 太傅), the Grand Guardian (taibao 太保), the Minister of Works (sikong 司空), the Minister of Education (situ 司徒), and the Commander-in-chief (dasima 大司馬) and the General-in-chief (dajiangjun 大將軍). Their staff was arranged in different sections (cao 曹). Regular court officials, arranged in courts (fu 府 or si 寺) helped to organize the imperial household affairs as chamberlains (qing 卿). The major institution of the Han central government, the Imperial Secretariat (shangshusheng 尚書省), was ousted to a more routinely administrative role that controlled the Six Ministries (liubu 六部, each headed by a minister shangshu 尚書 and a vice-minister puye 僕射). Instead, the executive policy-formulating powers belonged to the Palace Secretariat (zhongshusheng 中書省) that was the channel through which all memorials and documents flowed to the emperor and it was the agency that proposed and drafted all imperial rescipts, decrees (zhao 詔) and edicts (ling 令). Policy consultants were gathered in an institution called Chancellery (menxiasheng 門下省) whose main function was to advise and to remonstrate. The surveying agency of the officialdom was the Censorate (yushitai 衘史臺), headed by the Censor-in-chief (yushi dafu 衘史大夫).
The territory of the empire was divided into regions or provinces (zhou 州, governed by regional governors zhoumu 州牧 and controlled by regional inspectors, cishi 刺史), commanderies (jun 郡, administered by governors taishou 太守), and districts (xian 縣, governed by magistrates ling 令). Most regional governors were concurrently acting as military area commanders (dudu 都督 or zongguan 總管). Alongside with commanderies and districts there existed a lot of princedoms (wangguo 王國) and marquisates (houguo 侯國), territories bestowed to members of the imperial house and, particularly the marquisates, to ministers of high merits. Under the Wei dynasty, military agro-colonies (tuntian 屯田) had the size of commanderies and were independently administered by special officials (diannongli 典農吏). The Wei dynasty established a kind of rank classification in nine grades (jiupin 九品) for state offices. The access to offices was still open to free decision of superiors, although formally a Confucian education process had to be implemented by the National University (taixue 太學).
The military was constituted from a Capital Army that was garrisoned in and around the capital, the armies of the princedoms and imperial clansmen, and private armies (buqu 部曲) of the magnates that were scattered throughout the empire and often represented a challenge for the central government in cases of rebellion. The more civil-oriented goverments of the Southern Dynasties often in vain tried to reduce the force level of the national army and that of the princes, because there was a greater need to maintain a large army for the northern Dynasties because of the permanent danger of raids from neighbouring states.