AbstractThe technique of thin‐layer chromatography has been applied to the separation and identification of some tropolones on phosphoric acid impregnated, non‐bound cellulose powder. This method is simple, rapid and effective,Rj‐values of ten natural occurring tropolones are reported. The presence of ϵ‐thujaplicinol, ϵ‐ and γ‐thujaplicin in the wood extract ofLibocedrus formosan