Abstract:    Understanding the impact of scientific knowledge on the technological catch-up of latecomer economies is of great significance to innovation economics theory and public policy. This paper combined the theory of knowledge base and technological regime to construct a theoretical framework for analyzing the scientific knowledge characteristics of technological innovation across different sectors from the perspective of heterogeneity of scientific knowledge. It proposed five dimensions, namely, scientific linkage, scientific cumulativeness, scientific appropriability, scientific diversity and scientific knowledge sources, to define the characteristics of scientific knowledge used in technological innovation across different sectors, and analyzed their impacts on the technological catch-up of China. The data were obtained from the United States Patent and Trademark Office (USPTO) and Lens dataset. This covers a total of 5,100,624 patents in 88 economies granted by USPTO from 1995 to 2019, and 5,837,518 resolved scientific literature. Based on the WIPO technology classification table, the sample patents were divided into 35 technology fields according to their first IPC code. The generalized least squares (GLS) model was used to analyze impacts of scientific-technological regimes on technological catch-up in China. The following four research findings were obtained from this research. First, it is difficult for China to catch up in the fields characterized with high degree of scientific linkage. Sectors characterized with high scientific linkage, such as nanotechnology, biotechnology and chemical pharmaceuticals, rely heavily on new discoveries and basic scientific research knowledge. Compared with developed economies, China needs to accumulate scientific knowledge foundations and improve its absorption and transformation capabilities in the long term, in order to stimulate a virtuous interaction between subsequent scientific output and technological innovation.Second, China is more likely to gain technological advantages in the fields that rely on relatively recent scientific research knowledge. These fields require less scientific accumulation and rely more on newly published scientific research knowledge, which favors emerging economies′ technological catch-up. Meanwhile, foreign scientific research presents a significant positive effect on China′s technological innovation. The development of relatively advantage industries in China heavily rely on foreign scientific knowledge. Expanding the geographic boundaries of scientific knowledge sources acts as an important way for latecomer economies to absorb heterogeneous and complementary scientific knowledge and enhance their innovation capabilities. Third, China faces difficulties in gaining technological advantages in sectors characterized with high diversity of scientific knowledge. Organizations with different knowledge endowments present significant differences in innovation motives and patterns. Chinese inventors have weaker abilities to master complex scientific knowledge and rely more on knowledge in narrow domains in the process of scientific knowledge transfer. They have not been able to effectively utilize the achievements of multiple scientific knowledge fields to generate high-quality innovation. Technology innovators need to have a certain depth and breadth of knowledge to combine the scientific knowledge required for technological innovation and carry out subsequent integrated innovation.Finally, it is difficult for China to gain technological advantages in sectors where contribution of corporate science is high. Private basic research plays an important role in innovation in such sectors. It is hard for firms to transform scientific knowledge into technological innovation without enough efforts in understanding and absorbing cutting-edge science. The domestic scientific knowledge cited by Chinese patents are mainly produced by public institutions. In contrast, developed economies have a higher proportion basic research investment in private sectors, resulting in outstanding technological innovation, especially in science-intensive fields. These research findings will contribute to understanding the impacts of scientific knowledge to innovation, as well as characteristics of scientific knowledge of advantageous technological fields in China, thus providing policy implications for technological catch-up. This will deepen the theories of technological regime and enrich empirical evidences on the relationship between science and technology. 

Key words: scientific knowledge, non-patent reference, characteristics of science and technology, latecomer economies, technological catch-up