Abstract: The amount of patents is one of the key indicators to measure the innovation capability of a company and even a country. However, a lot of low-quality patents are emerging in China, which delay the development of Chinese companies and they call for clear patent strategies to effectively strengthen their values. To encourage companies to launch a set of patent application, Chinese government of all levels has introduced a series of policies. But whether patents facilitate the growth of companies and enhance their competitiveness has not yet reached an agreement. So there is a necessity to explore what the roles different types of patents play in reinforcing the development of companies.The primary aim of this study is to examine the impact of patent portfolio on corporate value, and test whether patents with different degree of innovativeness have variance regarding the influence on corporate value. Existing research has not yet come to a consensus on the impact of patent on listed manufacturing corporate value. This study chooses the listed manufacturing companies in Shanghai from the year 2012 to 2016 as research objectives and explores the relations between patent portfolio and corporate value of listed manufacturing companies in Shanghai.This research collected data from the listed manufacturing companies in Shanghai from the year 2012 to 2016. To analyze the associations among all the parameters, we formulated an empirical model drawing on Tobin’s Q coefficient theory, and tested the model with multiple regression analysis.First, the amount of patents can effectively enhance corporate value, especially those patents with high quality and high innovativeness. Corporate value can be significantly advanced by adding the number of the invention patents if there is a high proportion of the invention patents in the portfolio. Second, the impact of patents on corporate value depends on their innovativeness, and patents with high innovativeness have a more significant contribution to corporate value. Due to their high innovativeness, invention patents can effectively strengthen corporate value. But we have found no significant influence of utility model and design patent on listed manufacturing corporate value. Third, among the three types of patents, invention patents have a high proportion, which shows the listed manufacturing companies in Shanghai treasure the invention patents most.This study has some limitations in terms of the measurement of patents. We use the number of patent as quantitative indicator, and distinguish patent’s quality depending on its types, which may have bias on our findings. Future research could consider using patent citation to measure its quality and strengthen research validity.This study provides theoretical reference for manufacturing companies in Shanghai to formulate patent portfolio strategy, thus effectively enhancing corporate value and facilitating a better government patent subsidy policy.This study contributes to the literature in two ways: first,this study focuses on the effect of patent portfolio on corporate value, extending the relations between patent and corporate value; and second, this study explicitly explores the different effects of all three types of patents on corporate value, enriching the research on parents and corporate value.

Key words: patent portfolio, corporate value, technological innovation, manufacturing industry, patent strategy