This work of doctoral thesis determines the impact of the regional integration of Burundi into EAC on its economy growth and on the flow of FDI. A theoretical approach based on document exploitation supported by most recent data and case study has been used to address this question structured in four chapters. The first chapter is consecrated to the general overview FDI and macroeconomic indicators. We have shown the FDI theory, some main determinants of FDI in Burundi and also we showed the theory of macroeconomic indicators of performance. We remarked that on some variables, FDI have a negative or positive relationship in theory; we showed the main sectors of its economy and the main constraints in order to attract more FDI. The second chapter is entirely concerned with EAC integration process where we showed the history and stages of its integration process. The decision for re-establishing the East African Community is a right decision taken at the right time. It is a right decision that will enable East African partner states to withstand and the forces of globalization, provide an enabling environment for attracting foreign direct investments.