Despite economic progress made in quite a number of countries in the former ‘Third World’, between 20% to 50% of the world population is still excluded from this progress. By taking sustainable livelihood as a point of departure and by paying attention to actor-structure inter-actions, this paper conceptualizes these processes of social inclusion and exclusion. Livelihood is represented as a whole of dynamic interactions between actors and five vital capitals i.e. human, natural, physical, financial and social capital. These vital capitals are embedded in a social, economic, political and ecological structure. Interaction between actors and structure occurs via access and agency and results in processing of capitals to build livelihood. Livelihood is sustainable if it is capable of adequately satisfying self-defined needs and securing people against shocks and stresses put on capitals by structural factors. Livelihood strategies develop in arenas of conflicting or co-operating actors. Because livelihood strategies are multiple, individuals may belong to different interest groups and therefore social inclusion and exclusion is never rigid. Globalization is interpreted as localization, meaning a close association between homogenization and diversity or between the global and the local. Diversity it is not limited to socio-cultural domains but observed in economic and political domains too. Globalization-localization has important consequences for livelihood. The importance of the international and the local level will increase to the detriment of the national level. On the one hand,livelihood will become increasingly world wide and therefore multi-local. The different levels of scale in vital capitals and in structure come closer to each other and perhaps will even fuse. The arena will become increasingly global and livelihood strategies will become more homogenous. On the other hand,certain local characteristics of the arena remain or will even become more marked, and consequently livelihood strategies will need to become more specific too. Nevertheless,it is doubtful whether social exclusion will become a thing of the past. Therefore, global governance should have an important role in promoting sustainability of livelihoods. Global governance is explained as a global co-ordination by supra-regional and international governmental institutions of national governments balanced by an emerging international ‘civil society’. Both have a task in the regulation of global markets and development co-operation will have to develop towards a global social security system.As a result, it is concluded that research on sustainable livelihood will increasingly have to become multi-dimensional,multi-local and reciprocal.