The city of Hulunbuir and the Hinggan League in eastern Inner Mongolia straddle the borders between China, Russia and Mongolia. Transnational marriage has become a common social phenomenon in these multi-ethnic, multi-cultural zones. This study provides a preliminary analysis of the existing status and factors that contribute to transnational marriage in the region using the methods of literature, interview, and observation for data collection. The findings reveals that the transnational marriage in this region are mainly related to citizens of Japan, South Korea, Mongolia, the United States, Russia, Vietnam, Canada, Australia, the United Kingdom and other countries, showing complex regional and gender differences. The contributing factors on the process of transnational marriages is both direct and indirect. The current state of transnational marriage in northern cross-border regions is mostly shaped by the shared cultural traits of the neighboring ethnic groups, the attractiveness of different cultures, and the impact of economic gaps. Through the analysis, the author highlights the instrumentalist consideration, and the decisive effects of cultural and economic influences in the cross-border marriages.