Abstract:From the acetone extractive of lichen Lobaria isidiophora Yoshim. a new depsidone isidiophorin ( 1) together with 8 known compounds are isolated. Stictic acid, norstictic acid, cryptostictic acid, lecanoric acid, retigeric acid A, B, and methyl, ethyl orsellinates were identified. The structure of isidiophorin was elucidated on the basis of spectra and chemical methods.