This study examines whether R&D investments are non-linearly related to firm value. Using a sample of 563 Chinese listed firms between 2005 and 2013, we find that R&D investments have an inverted U-shaped relationship with firm value. This finding indicates that as R&D investments increase, firm value increases to a certain level and then decreases. We further find the presence of an inverted U-shaped relationship in firms with low state ownership. However, we find no evidence of a non-linear relationship in firms with high state ownership. These results suggest that the inverted U-shaped relationship is more pronounced for firms with low state ownership than for firms with high state ownership. Moreover, we find that there is an inverted U-shaped relationship between R&D investments and firm value in firms with high growth opportunities. In contrast, for firms with low growth opportunities, their relationship has a U-shaped pattern. These results are robust to robust standard errors clustered at the firm level, controlling for industry fixed effects, and omitting variable biases. Overall, our empirical evidence extends and complements the literature on the R&D investments-firm value relationship by considering their non-linear pattern. This study provides important implications for stakeholders, such as investors, policy makers, standard-setters, state owners, and regulators. Specifically, our findings can be useful to policy makers who pursue long-term performance objectives.Sustainability 2018, 10, 4133 2 of 17 the growth of new industries. China's total spending on research and development is estimated to have been 1.76 trillion yuan (around $279 billion) in 2017 [13]. R&D growth in Chinese firms had led the global market in its scale and scope by capitalizing their advantages in competitive costs to promote innovation and reap the technological capabilities for success in the world market [14]. Second, in China, both state-owned enterprises (SOEs) and private firms coexist. In particular, SOEs account for a substantial proportion of China's economy and their political connection with the Chinese government likely facilitate investment financing [15,16], enabling them to invest in more R&D. Similarly, Wu [17] points out that SOEs are likely to engage in more R&D investments.We test a non-linear relationship between R&D investments and firm value using a sample of 563 Chinese listed firms between 2005 and 2013. In our analyses, we employ three estimation specifications, such as pooled ordinary least squares (OLS) regressions, fixed-effect panel regressions, and dynamic panel generalized method of moments (GMM) estimators. We find that R&D investments have an inverted U-shaped relationship with firm value. As an additional analysis, we also examined the association between R&D investments and firm value in terms of high and low state ownership. We find that there is an inverted U-shaped pattern between R&D investments and firm value in firms with low state ownership. However, we find no evidence of a non-linear...