The nine rank system, or much less commonly nine grade controller system, was a civil service nomination system during the Three Kingdoms and the Southern and Northern Dynasties in China. Chen Qun, a court official of the Kingdom of Wei standardized its details.
Theoretically, local government authorities were given the task of selecting talented candidates, then categorizing them into nine grades depending on their abilities. In practice, however, only the rich and powerful would be selected.
Ranking of officials
During the Tang dynasty, the nine-rank system developed into a method of classification for civil officials and military officers serving the court, from local levels to national levels. Those directly under the Emperor heading the top departments were considered First Pin (Grade), and those who are county judicial officers, for example, were generally Ninth Pin. Some of the nine grades were further divided into zhèng (正; regular), cóng (從; deputy), shàng (上; upper) and xià (下; lower) grades. Therefore, in theory, the whole classification system actually holds more than eighteen ranks. In reality the subdivisions were customized in specific central and local departments; for instance, one department consisted of twelve ranks whereas another composed of sixteen.
The current Chinese cadre ranking system is loosely based on this historical system.