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.
郡县制
郡县制起源于春秋时期，秦始皇统一六国后正式推行全国，秦汉以后成为地方最基础的行政管理制度。郡，是在中央政府管理下的最高一级的地方行政机构，设郡守为最高行政长官。县，是郡的下级行政机构，设县令为最高行政长官。县、郡、中央政府与皇帝之间等级分明，构成了一个金字塔式的权力结构。在郡县制中，中央垂直管理地方，地方行政长官由皇帝直接任免，并在一定任期内进行流换。郡县制从根本上改变了西周以来分封割据的状况，打破了贵族势力对政府职务的垄断，成为官僚政治取代贵族政治的标志， 对于加强中央集权，维护国家统一具有重要意义。
郡县制是大一统国家的制度基石，推动古代大一统国家的建立。郡县制对中国地方行政制度影响深远，中国现行的行政区划制度就是在传统郡县制的基础上演变和发展来的。
