Abstract
The author in their article considers the USSR state policy in the field of protecting the border zone with China in the Kazakh-Xinjiang section of the border in the 1920-1930s. The purpose of the study is to show the migration processes and economic practices of the border territories population during the period of transition, from a period of frequent contact to the erection of a barrier on the border. The research is based on the legal acts regulating the border regime and the departmental records of the OGPU on border protection issues. The author shows the nature of the border during this period, firstly, it existed as a line of state demarcation and a military-political boundary, and secondly, it existed as a border contact territory, with established economic and migration practices. The author comes to the conclusion that even in the context of tightening the border regime, the population of the border territories maintained economic interaction, resorting to illegal practices in order to survive and circumvent government restrictions.