This paper evaluates firms’ exporting responses to BRI and considers their heterogeneity in ownership types, product types, regional origin and trade mode. This is done by analyzing firm-product-destination level customs data from 2008 to 2016. Our empirical results show that aggregate export behavior increased significantly after BRI. However, ownership matters when evaluating firms’ reactions, with SOEs and foreign firms benefitting, but privately owned domestic firms not. Further, our results on regional heterogeneity suggests that “open through the west”, i.e., boosting the development of western regions in China, did not appear to work in the short term. Our findings show clearly the implications of BRI’s impact from a firm level perspective.