Abstract: In the transformation of the system of grassroots social administration in the Ming and Qing the division of jurisdiction among the prefectural and county and police officials has been a phenomenon that has captured much attention. This has been especially true for Guangdong which provides the most representative example.  Beginning in the mid Ming, the police bureau held direct jurisdiction over the countryside，in the early Qing jailers and postal relay assistants began to have jurisdiction，by the 5th year of Yongzheng reign the assistant county magistrate had jurisdiction，registrars and other junior officials alsowere assigned to villages one by one.  Ultimately in the 2nd year of Qianlong year the Board of Rites issued an order that expanded the jurisdiction of police officials from the localities to all of Guangdong province. In reality this was the beginning of the formation of level one administration units below the countylevel.  The judicial district of the local police chief inGuangdong Province，known as a "Bureau"(Si)，was replicated by other provinces across the whole nation thereafter. This signified the penetration of state power penetrates into the grass roots level beneath county.  Thus，the long standing viewpoint that takes the county as the base level of administration needs to be reconsidered.