在處於環太平洋火山帶及菲律賓海板塊跟歐亞大陸板塊相互碰撞交會之處的臺灣，地震往往帶來許多極大的災害與恐懼，如何運用有限的已知資訊去預警地震，並有效降低地震所帶來的災害，是一個重要的課題。目前已知電離層濃 度變化與地震發生之前兆間，有其特定且複雜之關聯性，因此，本研究將討論應用階層式群聚分析能否鑑別有無地震發生的電離層全電子濃度變化之時間序列。

In Taiwan which locates in The Pacific Ring of Fire and the intersection of Philippine Sea Plate and Eurasian Plate, earthquake always brought lots of disasters and fear. Furthermore, It is an important topic that how to forecast earthquakes early by using the finite information for reducing the loss in the disaster of earthquakes. Recently there are special and complex relations between earthquake and total electron content was noted. In this study, therefore, we would discuss that if we can judge earthquake by total electron content time series with hierarchical cluster analysis.