臺灣的癌症發生率及死亡率有連年增加的趨勢，研究指出原因可能與環境中的污染物質有關，檢測可能的污染源附近是否存在癌症群聚(Cluster)，將有助於未來的癌症防治。在空間統計(Spatial Statistics)有不少方法可用於檢測群聚現象，其中用來檢測某個特定位置周圍是否發生群聚的方法被稱為焦點檢定(Focused Test)，本文介紹及評估常用的焦點檢定方法，並使用較佳方法探討臺灣地區疑似污染源的地區。 首先本文使用電腦模擬，在不同情境假設下比較焦點檢定方法的檢定力(Power)，例如研究區域大小、群聚形狀等不同的情境，以判斷檢定方法之間的優劣。最後本文分析臺灣鄉鎮市(Township)層級癌症死亡資料，應用焦點檢定方法分析石門核一廠、恆春核三廠及麥寮六輕周圍的癌症死亡率，檢定結果發現核一廠及麥寮六輕附近有較高的癌症死亡率。 / The cancer incidence and mortality rate in Taiwan have been increasing over the past 30 years. Previous studies indicate that the pollution sources, especially for those creating air pollution and excess radiation, are one of the potential causes for the increment. Correctly, detecting the location of possible sources of contaminants can help for cancer prevention. In spatial statistics, focused test can be used to determine if the intensity rate are higher around a possible pollution source. We will introduce and evaluate frequently used focused tests and apply them in Taiwan. First we use computer simulation to compare the power of focused tests in different scenarios, such as study region and cluster shape. Next, we apply the focused tests to Taiwan cancer mortality data, in order to decide if the cancer mortality rates are higher around Chinshan nuclear power plant, Maanshan nuclear power plant, and Mailiao sixth naphtha cracker. The results show that the cancer mortality rates around Chinshan nuclear power plant and Mailiao sixth naphtha cracker are significantly higher.