According to the rules of the Ming Dynasty

the civil officials graded above the fourth level in the south and north capitals should all be investigated every six years

which called capital official assessment. During the capital official assessment

the senior officials graded above fourth level were endowed with the privilege to resign by sending self-defense text in order to incarnate the preferential treatment for them. This article applies the capital officials’ self-inspection memorial to the throne as the carrier of research and demonstrates the dynamic operation characteristics of the self-inspection institution by systematically studying the characteristic

writing method and circulation mechanism of self-inspection text. While exploring the decisive basis and procedure of the officials investigation

we can find that the self-inspection institution worked as an information transmission channel which played an crucial role in the relationship between emperor and officials

although it failed to achieve the purpose of weeding out incompetent officials. This was the key reason why the self-inspection institution could be steadily operated for hundreds of years in the Ming Dynasty and the Qing Dynasty.