Political Subdivision: Commanderies and Counties
Division into commanderies and counties can be traced back to the Spring and Autumn period (770-476 B.C.). However, it was not until Qinshihuang conquered the other six states that the idea of political subdivision was officially implemented nationwide. Commanderies and counties emerged as dominant units of local government after the Qin (221-206 B.C.) and Han (206 B.C. - A.D. 220) dynasties. The commandery, headed by the governor, was the highest level of local government under the central government. Administrative divisions under a commandery were called counties, headed by county magistrates. This hierarchical relationship between counties, com- manderies, the central government, and the emperor constituted a pyramid-like power structure. In this structure, the central government vertically oversaw local affairs and exercised oversight over the performance of local officials, and local chief administrators were appointed and removed directly by the emperor and might be subject to rotation. The introduction of this structure fundamentally changed the landscape of local government dominated by self-contained, separate fiefdoms that had existed since the Western Zhou Dynasty (1046-771 B.C.), and broke the aristocracy's monopoly of government positions. It heralded the emergence of the bureaucratic class in place of the aristocracy and was crucial to strengthening centralization and maintaining national unity.
This political subdivision system provided an institutional basis for "grand unity" in ancient China that led to the establishment of a unified country. It has had a far-reaching impact on China's local administration, and China's current administrative division system has evolved from its ancient predecessor.
郡縣制
郡縣制起源于春秋時期，秦始皇統一六國后正式推行全國，秦漢以后成為地方最基礎的行政管理制度。郡，是在中央政府管理下的最高一級的地方行政機構，設郡守為最高行政長官。縣，是郡的下級行政機構，設縣令為最高行政長官。縣、郡、中央政府與皇帝之間等級分明，構成了一個金字塔式的權力結構。在郡縣制中，中央垂直管理地方，地方行政長官由皇帝直接任免，并在一定任期內進行流換。郡縣制從根本上改變了西周以來分封割據的狀況，打破了貴族勢力對政府職務的壟斷，成為官僚政治取代貴族政治的標志， 對于加強中央集權，維護國家統一具有重要意義。
郡縣制是大一統國家的制度基石，推動古代大一統國家的建立。郡縣制對中國地方行政制度影響深遠，中國現行的行政區劃制度就是在傳統郡縣制的基礎上演變和發展來的。
