本研究目的係評估紅檜 (Chamaecyparis formosensis)、臺灣扁柏 (C. obtusa var.formosana)、臺灣肖楠 (Calocedrus macrolepis var. formosana)、臺灣杉 (Taiwaniacryptomerioides) 及香杉 (Cunninghamia konishii) 等5種臺灣針葉五木材部精油的抗真菌活性和抗白蟻活性。試驗結果顯示，紅檜材部精油的抑菌效果最好，對Trametes versicolor和Lenzites betulina 2株白腐菌之半數抑制濃度 (IC ) 分別為20.8 5 0 μg/mL和24.8 μg/mL；對Laetiporus sulphureus和Gloeophyllum trabeum 2株褐腐菌之半數抑制濃度分別為32.7μg/mL和27.9 μg/mL。另外，比較5種材部精油抗臺灣家白蟻 (Coptotermes formosanus) 之活性，紅檜材部精油毒殺臺灣家白蟻的效果最強，其半數致死量 (LD50) 為0.87 mg/g，其次為臺灣扁柏材部精油 (0.91 mg/g)。至於紅檜和臺灣扁柏材部精油成分之分析，紅檜材部精油以Myrtenol + Myrtenal (9.64%)、α-Costol (9.32%) 和 α-Cadinol (7.93%) 為主成分；臺灣扁柏材部精油主成分以δ-Cadinene (28.97%) 為主。綜合上述結果得知，紅檜材部精油具有良好的抗真菌活性及抗白蟻活性；臺灣扁柏材部精油具有良好的抗白蟻活性，非常值得進一步開發成環境友善的抗真菌藥劑或抗白蟻藥劑。

This study evaluated the antifungal and antitermitic activities of wood essential oils from five indigenous conifers (Chamaecyparis formosensis, C. obtusa var. formosana, Calocedrus macrolepis var. formosana, Taiwania cryptomerioides and Cunninghamia konishii) in Taiwan against four wood-rot fungi and Formosan subterranean termite (Coptotermes formosanus). Results showed that wood essential oil of C. formosensis had the strongest antifungal activities, with the IC values of 20.8 μg/mL and 24.8 μg/mL for Trametes versicolor 50 and Lenzites betulina; with the IC values of 32.7 μg/mL and 27.9 μg/mL for Laetiporus 50 sulphureus and Gloeophyllum trabeum. Besides, comparion results of the antitermitic activities of wood essential oils from the aforementioned five indigenous conifers showed that the wood essential oils of C. formosensis and C. obtusa var. formosana had excellent antitermitic activities, with LD values of 0.87 mg/g and 0.91 mg/g after 7 d of testing, respectively. According to the 50 constituents of wood essential oils from C. formosensis and C. obtusa var. formosana and their relative contents obtained from GC-MS analyses, major constituents in C. formosensis wood essenstail oil were myrtenol + myrtenal (9.64%), α-costol (9.32%) and α-cadinol (7.93%). In addition, the main constituent of C. obtusa var. formosana wood essentail oil was δ-cadinene (28.97%). Moreover, our results revealed that the wood essential oil of C. formosensis had excellent antifungal and antitermitic activities, and that of C. obtusa var. formosana had good antitermitic activity. It suggests that either one has the potential to be further developed into ecofriendly antifungal or termite control agents.