This study seeks to present effective policy measures for win-win cooperation that reflects the industrial characteristics of the Daejeon and Sejong regions.Recently, through win-win cooperation between local governments, a close mutually complementary relationship is maintained for the common goal of supplementing administrative and legislative capabilities in areas such as economy, development, and provision of administrative services, and mutual benefit is achieved through symbiotic business relationships. Efforts are being made to improve. In this process, the transportation network connecting the Daejeon and Sejong regions is being improved in connection with the megacities in the Chungcheong region, and this transportation network is a key factor in balanced regional development, creating a virtuous cycle of regional growth and regional development policies through regional connection. In this process, the market integration of the Daejeon and Sejong regions predicts changes in inter-industry competition, and more precise analysis and effective response measures are needed to confirm the effective inter-industry characteristics of mutual development between regions. In this study, we confirm the characteristics of inter-regional urban coexistence development plans and the direction of research through related previous research, and derive key characteristics through the main industries and promising growth industries in the Daejeon and Sejong regions in the regional status. Next, we use the Herfindahl-Hirschman Index (HHI) to analyze competition and coexistence by industry to identify the industrial economic structure of the Daejeon and Sejong regions and industrial areas that can cooperate. Through these research results, we aim to identify industries with high industrial convergence and their characteristics from the perspective of competitive structure, and present policy implications that reflect the meaning of win-win cooperation and industrial characteristics between the Daejeon and Sejong regions.