《资治通鉴·晋纪·晋纪三》
当初，陈群由于吏部不能够审查核实天下的士人，所以就命令郡国各自设置中正，州设置大中正，都选取本地区的人担任朝廷的官职，只有富于德才的人才能够当选。按照士人的才能、政绩、资历分为不同的九品等级。如果言行卓越显著就可以被提升，道义缺损的就被降级，吏部就凭借这个来补充朝廷的百官。
初，陈群以吏部不能审核天下之士，故令郡国各置中正，州置大中正，皆取本士之人任朝廷官，德充才盛者为之，使铨次等级以为九品，有言行修著则升之，道义亏缺则降之，吏部凭之以补授百官。
In the past, Chen Qun, because the Ministry of Personnel could not verify the scholars in the world, ordered the counties and states to set up Zhongzheng and the states to set up the chief Zhongzheng, to select local people to serve as imperial officials, only those with virtue and talent can be elected. According to the talents, political performance and qualifications of scholars, they are divided into nine different grades. If their words and deeds are outstanding, they can be promoted, and their moral deficiencies will be demoted. The Ministry of Personnel will use this to supplement the imperial officials.