| Zhenbian Subprefecture was located in the southwest of Yunnan Province and set up in fourteen years Guangxu (1888), whose setting up was an important initiative in the late Qing Dynasty in the southwest frontier of China.In this paper, we take Zhenbian Subprefecture for example to complete a case study of the frontier Administrative Region change affected by a variety of factors. The historical clue is the change of the empire’s rule order in the southwest Yunnan, in the early Qing Dynasty the Menglian chieftain out of the empire’s control came back into the rule; in the middle of the Qing Dynasty, the experienced disorder and recovery process; in the late Qing dynasty, the empire’s rule in Southwest Yunnan experienced disorder and recovery process again, and finally the southwest Yunnan became into an administrative region consistent with the Mainland. It presents us with a historical process in which a frontier area ruled by Tusi was turned into a county, and the process provides us a case to think about the ethnic social change mode in the frontier.In this paper, by analyzing the various factors affecting the empire’s frontier measures in the southwest border of Yunnan in different historical stages and their interactions, we research for the dominant factor impacting the empire’s frontier administrative region setting. This paper argues that the dominant factor is the empire’s frontier strategy in a certain historical stage. Either a Tusi administrative region or a formal official administrative region, they are both the empire’s frontier control strategy means, the implementation of the border. In addition, the analysis about the establishment of Zhenbian Subprefecture leads us to reflect on the role of the requirements in the frontier administrative region establishment which was summarized in the traditional study.The article consists mainly of four parts, the first part provides the main spatial and temporal background of the text; the second takes the changing role of Menglian chieftain as the empire’s border agents during17-19Century as the theme, researching in the change of empire’s attitudes and policies about Menglian chieftain in the transformation of Menglian chieftain’s role in the frontier. The third part mainly analyzes various factors affecting the setting of Zhenbian Subprefecture, and think of the role of each one respectively plays in Zhenbian Subprefecture setting from three aspects border crisis, local social deterioration of the ruling order and local governors Personal factors. The fourth evaluates if the setting of Zhenbian Subprefecture achieves the expected purpose, and this chapter selects four different perspectives to make an assessment. |