This paper studies how infrastructure contributes to long-run economic growth and transitional convergence with institutions as a mediating factor in China. Using a panel dataset of 30 Chinese provinces from 1998 to 2018 and a variety of estimators, the paper finds overwhelming support to the positive effect of infrastructure on growth and highlights regional heterogeneity in the importance of institutions. The results show institutions play a determining role in infrastructure’s productivity for less developed economies. The results also disentangle infrastructure’s effects in the long-run (0.33) and short-run (-0.04-0.16), adding insights to its dynamic path and illuminate its significance as a condition for regional growth convergence – Chinese provinces catch up in about 20 years controlling for infrastructure and institutions. The joint effects of the infrastructure-institution interaction also generate development and policy implications that would be applicable for developing and transitioning economies alike.