This dissertation will look at how the trade and investment relations between the European Union (EU) and China will change in the twenty-first century especially after China joined the World Trade Organization (WTO) and after the EU enlargement. The purpose of this study is to draw out and analyze the challenges and opportunities generated from this deepening of EU-China trade and investment relations, and how all these could eventually assist China and the EU in pursuing further prosperity and stability in both economies. This also revokes how the policy makers of both regions would come up with better set of foreign trade policies and measures so as to promote effective multilateralism in the global economy. Attention will be focused particularly towards the aspects of trade and investment between the two countries in the macro economic context; how this whole process will affect the structure and level of their trade and investment developments in the near future. The study has made use of official statistical data about their economic and trade co-operation since 1975 when the first official bilateral relations between the European Economic Community and the People's Republic of China (EEC-China Trade Agreement) was established; and therefore what more has been achieved between the two sides over the course of these few decades. This research will try to analyze the policy agendas of the two countries and to explore the challenges and opportunities faced by the two sides in the setting of a changing global economy of the twenty-first century. All in all, the ultimate objectives of this thesis are to give recommendations to the economic and trade policies made by the EU and China based on their past co-operation experience for enhancing a more comprehensive and strategic partnership with better sustainable growth for in the near future. And we will also try to explore the tendency of the future developments of the EU-China trade and economic relations. Finally, it will also provide a clear picture about the trade and investment environment of these two countries for all global traders and investors. Key words: EU-China trade and investment relations, bilateral trade and investment policies, EU enlargement, opportunities and challenges, bilateral trade disputes