R&D internationalisation is widely observed during the last few decades and also believed to provide a vehicle for firms to access to, and extract benefits from a target country’s technical resources, scientific talent, and local expertise. However, most of these studies focused on developed country firms which were responsible for the bulk of global R&D. This paper aims to offer some empirical evidence of why and how the Chinese firms began to internationalism their R&D activities. Based on a field study on the R&D internationalisation of Chinese multinational enterprises (MNEs) since 2005, this research provides new insights to the topic of the R&D internationalization by carrying out empirical study on developing country firms. In contrast to developed country MNEs, Chinese MNEs internationalize their R&D in order to explore technology and capability in both developed and developing countries, with limited exploitation purpose in developing countries; they are difficult to integrate global R&D network so as to maximize the efficiency of their R&D activity; and they face unique challenges including not only weak R&D and management capability but also the fundamentally weak national innovation system which constrain them to learn and absorb in international market in addition to the advanced ICT which limit them to communicate and coordinate between their R&D units. We anticipated that the results from this research would offer an opportunity to better understand the R&D internationalization by taking the unique features of the R&D internationalization of developing country MNEs into account.