The objective of this research is to clarify empirically the influence of the network structure between companies on research and development (R&D) in Internet of Things (IoT) business. In IoT business, R&D beyond the border of a company becomes important. Furthermore, advantageous positioning in the network is thought to enhance the result of R&D, and ultimately contribute to profit. In this research, the relationship between the network structure and the result of R&D was analyzed with a method of social network analysis. Joint-application patents related to IoT business were extracted from the intellectual-property database. As a result, the difference in the network structure of a company was related to the result of R&D and profitability in IoT business.