Abstract: The global geopolitical pattern is the matter of development and stability of international situation. Force structure is an important part of geopolitical pattern. The study of force structure evolution would be helpful for practice of geopolitics, depth analysis of potential signatures and evolvement rule about force structure and grasping accurately logical relationship between the current global geopolitical pattern and the past one. The force structure was built on the basic of the research of the history evolution about global geopolitical pattern by using social network analysis and then this paper calculated parameters of it, such as the centrality, Hubbell Influence, connectedness and cohesion degree. The different Characteristics of power centers could be gotten by the horizontal comparison of parameters.By the longitudinal analysis of network parameters, the change of network parameters could be gotten, which were in the process of different types of global geopolitical patterns. The force structure evolution process of quantitative change to qualitative can be found by clustering analysis.