This thesis aims to discuss regional security in Central-Eastern Europe (CEE) and analysis its development and challenge. In order to fit in with the purpose exploring approach of trans-theoretical analysis, this thesis aims to collect literatures about Analytical Eclecticism and apply it to CCE case study for comprehensive observation. Given the preliminary stage domestic research community has been, we expect to provide the more understanding, debating, and applying of Analytical Eclecticism in IR field.