The Internet expands the field for international politics. It unveils its inner operational logic by exerting its influence on international politics. The Internet，by either guiding or negating the conducts of actors through its own unique innate quality，forces these actors to obey its inherent laws so as to better maintain their own interests. Firstly，this paper attempts to reveal，through level analysis，how the Internet made an impact on international politics，namely by the route of the individual，state and international system. Secondly，taking state interest，power and security as the core of Internet’s action on international politics，it demonstrates that there is no absolute Internet freedom and that the interests and security of the state come before all. The third part of the paper illustrates the catalytical，synchronical and constructional role of the Internet in promoting the transition of international structure. As an information medium，the Internet helps promote changes in international politics. As an advanced technology，it helps international politics constantly identify itself with the development of the times. The all-inclusive interactive communication following the advent of microblogs and Social Networking Services（SNS）helps provide conditions in which international society is evolving itself into a world society in the world of Internet.