Abstract: Based on the concept connotation of open economy, this paper builds the evaluation index system for open economy in border cities from opening to the outside world and opening to the interior. Taking Hunchun City, China as an example, the entropy method, coupling coordination model and obstacle degree model were used to explore the development process, characteristics and influencing factors of open economy in Hunchun from 2001 to 2020. The results are as follows: 1) The economic openness of Hunchun showed a trend of fluctuating upward, and the opening process has experienced three stages: slow development (2001-2008), rapid development (2009-2014) and stable development (2015-2020). Opening to the outside world and the interior have gradually transitioned from barely coordinated to well-coordinated. 2) During the study period, the obstacle degree of opening to the outside world showed a trend of fluctuating upward, while the obstacle degree of opening to the interior showed a trend of fluctuating downward. Opening to the outside world is the critical factor that restricts the opening development of Hunchun at its current stage. The main obstacle factors include degree of dependence on foreign trade, the number of newly approved foreign-funded enterprises, actual utilization of foreign capital and investment promotion.

Key words: border city, open economy, entropy method, influence factor, Hunchun City