Political System of the Yuan Empire

Although the whole Yuan period 元 (1279-1368) can be interpreted as a mere a military occupation of China than one of a real civilian government, able rulers like Emperor Shizong 元世祖 (Qubilai Khan, r. 1260-1294) saw that a high civilisation like China with a culture of immense absorbing potential for people entering her realm, would only be governeable with the instruments already existing. The Mongols took over the post relais (yi 驛) system of the Song 宋 (960-1279) administration, the system for taxation, granaries, state examinations for official recruitment, the paper money as a national currency, the imperial library and the historiographical offices. They left in place most Song institutions but imposed on them offices staffed with Mongol overseers called daruhaci (Chinese: zhangyinguan 掌印官 "sealholders") , even on a local level. Like during the Song period, the three central government offices were the Palace Secretariat (zhongshusheng 中書省) with the two counsellors (zaixiang 宰相 ), the Censorate (yushitai 御史臺) to maintain the disciplinary surveillance over the whole officialdom with two censors ((yushi dafu 御史大夫 ) as heads, and the Bureau of Military Affairs (shumiyuan 樞密院). The Censorate of the Mongols had greater influence than the Song period Censorate: it was allowed to exert certain direct punitive actions, and was authorized to criticize court policies and to propose new ones. The many other offices to maintain the palace service, the state rites, official recruitment by the Hanlin Academy (Hanlinyuan 翰林院 ), the imperial manufacturies of the Song time still existed, plus some bureaus for religious administration.
Territorial administration changed deeply. During the conquest of China, ad-hoc administration units were created, called "field secretariats" (xing zhongshusheng 行中書省). These very large units (at least compared to the lu 路 circuits of the Song empire) are the foundation of the modern provincial administration. A special unit was the large province of the metropolitan area around Khanbalik (Dadu 大都, modern Beijing) that was called Zhili 直隸 "directly attached province", a name that was in use until the 1920es. The other field secretariats ("provinces", sheng 省) of the Yuan empire were: Liaoyang 遼陽 (modern Liaoning and Jilin), Lingbei 岭北 (modern Inner Mongolia and the PR Mongolia), Shaanxi, Gansu, Sichuan, Yunnan, Jiangzhe 江浙 (modern Jiangsu and Zhejiang), Jiangxi (modern Jiangxi and Fujian), and Huguang 湖廣 (modern Hubei, Hunan, Guangdong and Guangxi). Outside of the borders of modern China, the Yuan empire inclued the north of Vietnam that was called Annan 安南 "Appeased South" (a name in use since Tang Dynasty), and Korea was called Zhengdong 征東 "Conquered East". Tibet as a vasall state was formally administered by a Foreign Politics Court (xuanzhengyuan 宣政院).
Each "province" was governed by branches of the central secretariat, the censorate and the military bureau. The province government was therewith a small copy of the central government. A smaller administration unit was the circuit (dao 道 ) with a "pacification" and a military commission or a surveillance commission. The route (lu 道) unit was administered both by central and some local institutions. The Song prefecture (superior: fu 府 ; inferior: zhou 州 ; military: jun 軍, industrial: jian 監) was still existant and governed by a Chinese prefect (zhifu 知府 or metropolital magistrate yin 尹 ) and a Mongol overseer. The district (xian 縣 ) was administered by a Chinese magistrate (yin 尹 ), a Mongol overseer and a Muslim (mainly Uyghurian) vice magistrate (cheng 丞). Like it was use since the Cao-Wei period 曹魏 (220-265), all officials were divided into nine ranks (jiupin 九品), with two subranks (shang 上, xia 下) each.
Even the army was divided into three different kinds of troops: the Mongol army, their allies, and Chinese troops.

Legal system:
During the first decades of Mongol rule over northern China, the law codexes of the Jin empire 金 (1115-1234) were not adopted. It was especially the Taihe lüyi 泰和律義 and Taihe lüling 泰和律令 codices from the beginning of the 13th century that were discarded by the Mongol conquerors. In practice, cases of daily routine were administered according to precedents (anli 案例), each single case being adjusted to circumstances. Legislation was a question of edicts (zhao 詔, zhi 制, ling 令, tiaoge 條格) issued by the emperor or the imperial secretariat and its bureaus. Law cases and the resulting judgments were written down as precedents and thus preserved for further consultation. This collection of precedents was published as "universal precedents" (tongli 通例) by the central government, and together with laws and edicts from earlier historical periods, these were published in the Yuan codexes Dayuan tongzhi 大元通制 and Zhizheng tiaoge 至正條格 in 1323. Yuan laws have only survived as fragments in the collection Tongzhi tiaoge 通制條格. Administrative matters on the local level were regulated by the Yuan dianzhang 元典章 "Yuan statutes" from 1322. These are a compilation of precedents collected by local officials.
In many aspects, Mongol law suppressed the Chinese population. It was forbidden for Chinese to possess weapons or to undertake military training, and - at least theoretically - the assembling of large groups to engage in market activities was prohibited. Mongols were exempted from death penalty for murder and had only to pay a certain fee for the burial. But generally spoken, penalties for crime became less strict than before, especially concerning the further observation of criminals and entries in their household registers. The influence of Mongol and Muslim customs can also be seen in severe punishments for the theft of cattle, or in special regulations for butchering animals.