AbstractThe phenolic part from the essential oil ofChamaecyparis taiwanensisMasamune et Suzuki, extractives ofChamaecyparis formosensis Matsum. andTaiwania cryptomerioidesHay. were studied by using polyamide thin‐layer chromatography. The presence of chamaecin, chamenol, thymol, carvacrol,m‐isopropylphenol andp‐cresol in the essential oil ofChamaecyparis taiwanensisMasamune et Suzuki was confirmed. Carvacrol, o‐isopropylphenol,m‐isopropylphenol,o‐cresol andp‐cresol were also detected from extractives ofChamaecyparis formosensisMatsum. The chromatogram ofTaiwania cryptomerioidesHay. showed the presence of 12 spots. Among these, the spot withRfvalue 0.37 was identified as TaiwaninBand that withRf. value 0.80