This thesis provides an in-depth and detailed examination of China-EU relations between 2001 and 2013. Specifically, it investigates the collaboration on Climate Change and Renewable Energy between China and the European Union. It departs from the conventional academic literature in the field, which has treated Sino-European relations as bilateral ties between Beijing and Brussels, as well as between China and the national capitals of the EU member states. Instead, it studies Sino-European relations by focusing on individual institutions and corporate organisations. To achieve this, this thesis investigates the foreign policy formation and execution process in Beijing. It offers a detailed examination of the relations between elements of the Chinese Communist Party, as the ultimate decision maker, the Chinese governmental institutions and the Chinese companies involved in renewable and climate sectors. It analyses the extent to which changes in foreign policy priorities and the growing numbers of players involved in Beijing’s foreign policy making process have altered China’s EU policy. It also investigates individual actors on the European side. In particular, it focuses on whether the European actors recognise changes in China’s foreign policy agenda as well as whether they have responded effectively to shifts in the institutional balance of power in Beijing. It uses Sino-European collaborations on Climate Change and Renewable Energy as case studies to answer the key research question “To what extent are China-EU relations pre-dominantly determined by the interests of a diverse range of foreign policy actors?” It thus identifies who shapes the bargaining process; on which policy each actor bargains with, and the outcomes of the relevant bargaining process. The thesis was conducted using qualitative research methods, especially a large number of in-depth interviews, many of them with members of the commercial and political elite, and drawing the secondary sources to corroborate the interview results.