The literature has extensively studied the impact of inter-city transportation infrastructure on firm production. However, the effect of intra-city transportation infrastructure on firm production remains unclear. In this study, we investigate the impact of subway station openings on the productivity of firms by using a difference-in-differences (DID) model. Our results suggest a positive impact of subway station openings on the productivity of firms. After excluding the influence of subsidiaries on the results, we find that this effect remains significant. We find evidence that firms with a more educated workforce benefit more from the proximity to a subway, and that labor productivity is enhanced for firms located close to subways.