Abstract: Cooperative R&D networks are effective channels for firms to obtain heterogeneous resources, and occupying key network positions can bring information and control advantages to firms. However, the existing literature has not yet reached a consistent conclusion on the relationship between network position transition and innovation. Focusing on the global biotechnology field, this paper selects a research sample of 264 firms during 1995-2016 to empirically analyze the effects of centrality transition and brokerage transition in collaborative R&D networks on firms’ breakthrough technological innovation, as well as the moderating role of the depth and width of firms’ knowledge bases. The results of the empirical study show that the centrality transition contributes to breakthrough technological innovation, while the brokerage transition has a U-shaped relationship with breakthrough technological innovation. Knowledge breadth positively moderates the relationship between the centrality transition and breakthrough technological innovation, but the moderating effect on the relationship between brokerage transition and breakthrough technological innovation is not significant. Knowledge depth negatively moderates the positive relationship between centrality transition and breakthrough technological innovation, but positively shapes the U-shaped relationship. The results of the study have important implications for understanding the complex relationship between network position transition and enterprise technological innovation.

Key words: collaborative R&D networks, network position transition, knowledge base, breakthrough technological innovation