Abstract: Industry-university research alliances (IURA) are an important national policy for Chinese government to accelerate technological innovation. However, it is still not clear that how IURA impact corporate innovation. Unlike prior studies, we analyzed the impact of IURA and its mechanism on corporate innovation to examine their policy effects based on IPC information of inventions, taking the companies of the ChiNext market as the research object. Our results show that IURA have a positive impact on technological diversification after using propensity score matching method and difference-in-differences regressions. Moreover, we further find that the impact has a significant lagged effect after using dynamic analysis model. This paper provides theory and empirical evidence for our insight into real effects of Chinese IURA policy. In addition, it also provides meaningful policy implications for China’s government and firms to perfect IURA policy and enhance innovation capability.