As the “Battle of Seattle” in 1999 and the later events show, today's anti-globalization movements are not only trans-national but also trans-issue, trans-gender, trans-generation, trans-ideology and trans-culture in nature. This essay tries to explain how and why the movements continue to expand while maintaining the association of such a diverse group of actors like environmentalists, labor unions, human rights activists, students, feminists, farmers, and consumer groups.<br>Section One is a conceptual analysis of anti-globalization. Since anti-globalization encompasses variety of meanings that are often vague and/or contradictory, conceptual clarification is a necessary first step for any empirical analyses. The conceptual analysis of anti-globalization requires to specify 1) who are, 2) against what, 3) for what reasons, 4) by which means and 5) to what degree. It is also necessary to conceptually distinguish anti-globalization and anti-globalism, because some actors can be, and actually are, anti-globalization but pro-globalism.<br>Section Two is the case study of one of the most widely recognized anti-globalization movements, the World Social Forum. The WSF started in 2001 to challenge the World Economic Forum (known as the Davos meeting). While the WEF is a gathering of pro-globalization leaders of states, business and academics in the North, the WSF is a forum of anti-globalization citizens from all over the world who meet once a year in the South, e.g., Brazil, India and Kenya. The WSF is so diverse in all of the five elements specified in the conceptual analysis that the agendas and interests of its participants are not always in harmony. But they all support the idea, as proclaimed in the WSF Charter of Principles, that “Another World is Possible” if they can replace the neo-liberal globalization with their “alter-globalization.”<br>Section Three discusses the result of the case study. The WSF could grow as “the network of networks” by enhancing three linkages among participants. The first is issue linkages; the WSF participants could find some common agendas that connect two or more different issue areas, e.g., the environment, labor, human rights, gender, agriculture and fair trade. The second is the global-local linkages; the WSF could form a “glocal” network by combining numerous local anti-globalization movements at the global level. The third is psychological linkages; the WSF could enhance the “we” feeling among participants by providing them with once-a-year big events of marching and discussions. The WSF does have some weaknesses and dilemmas, but those shortcomings are to be addressed by not only the anti-globalization groups but also the international society as a whole.