對等傳輸(P2P)技術已被廣泛地使用在大規模的內容傳輸應用上，如檔案分享及網路電視。然而，目前P2P技術仍無法支援實現大規模的即時性使用者互動情境。針對此一現象，本研究對於樹狀覆疊建構及最佳化方法進行概括性的分類介紹與討論，並以大規模實驗比較三種最佳化方法：傳輸成本最小化、根源延遲最小化、覆疊階層最小化。期望本研究能引發更多對於此議題的研究與討論。

P2P technologies have been popularly adopted in various applications of content distribution, such asfile sharing and Internet television. P2P technologies, however, still do not support large-scale real-timeapplications of user interactions. To get insight of and to breakthrough this quandary, this study made anoverall investigation about tree-based overlay construction and optimization, with a large-scale experiment forcomparing three types of optimization technologies: tree-cost optimization, root-delay optimization, tree-depthoptimization. This study is expected to motivate more researching works about this issue.