Karoowia saxeti was recorded during the lichen field expedition in southern part of Korea in 2006. The lichen was found on the rock surface along coastal line. This species was easily recognized by chemistry (K+ yellow) and the presence of isidia. Thallus was saxicolous, subcrustose, more or less lobate at the center with clearly lobed margins, $2{sim}6;cm$ broad and pale yellowish green. Thalli lobes were irregular, variable, up to 1.0mm wide, not branched, flat to more or less convex and contiguous to subimbricate. Upper surface of the thalli was continuous, emaculate, moderately isidiate. The isidia was subglobose to cynlindrical, darkening at the tips and unbranched. Low surface of the thalii was black with a spongy rhizoidal and lamellar layer. HPLC analysis proved the presence of stictic acid (K+ yellow), norstictic acid and usnic acid. This is the first record of the species in South Korea.