This thesis investigates how Chinese decision-makers deal with the complexities of EU foreign-policy making. Which of the many entities within in the EU, among Brussels-based institutions and in member states, do they approach and how? How can the modalities of engagement be explained? What patterns emerge and how and why do they change over time? In answering these questions, the thesis provides insights on three under-researched issues of international relations: first, on how outsiders engage with the EU and whether the EU is capable of managing requests from the outside; second, on how China makes its EU policy, and, by extension, to what extent its decision-making structure can deal with complex foreignpolicy challenges; third, and more generally, on how international actors interact through numerous contacts among the bureaucratic agents within them. To reach these goals, a new analytical framework is introduced that distinguishes three processes to explain such transnational bureaucratic interaction. First, the decisionmaking in China on how to engage the EU. Second, the reception this approach receives on the EU side. These first two processes are analysed as based on the interplay of organisational logic, bureaucratic politics, and the degree of central control. Third, there are independent dynamics of direct interaction between bureaucratic entities, which result from the quality of personal relations and the matches or mismatches in preferences, worldviews, and perceptions. Two intensive case studies are performed, one on China’s efforts to be recognised as a market economy by the EU, and another on the Chinese push to have the EU lift its arms embargo against China. The thesis proposes a threefold argument. First, due to complex formal rules and volatile informal patterns of EU foreign policy, the EU remains difficult to approach for third actors and is incapable of managing requests from the outside. Second, engaging a complex counterpart like the EU puts strain on the foreign-policy process. Chinese policy making suffers from strong horizontal divisions which prevent the distribution of expertise and hinder the formation of elaborate strategies for approaching the EU. Lastly, in order to explain the modalities of interaction between different actors in international affairs, it is crucial to look at how the bureaucratic agents involved in the foreign-policy process interact with their respective counterparts.