What influences foreign plaintiffs’ likelihood of winning intellectual property rights (IPR) lawsuits in an emerging economy such as China? From an institution-based view, prior scholarly debate presents two competing perspectives on the evolving IPR regime in China, focusing on the incentives of internal development and the pressures of external legitimacy respectively. We integrate these two perspectives to examine the effects of regional research and development (R&D) investment on the likelihood of foreign plaintiffs winning IPR lawsuits. We identify a direct effect reflecting the evolving economic incentives of host regions, and two mediating pathways that correspond to the legal strategies employed by foreign plaintiffs to apply external legitimacy pressure on host region legal institutions. Our analyses of a sample of 1103 IPR disputes between foreign plaintiffs and local defendants in Chinese courts from 2008 to 2017 provide support to our arguments.