Two new species, Thelopsis ullungdoensis and Phylloblastia gyeongsangbukensis are described from Ullung-Do (Island), South Korea. The closest relatives from Europe and Korea are epi phytic Thelopsis flaveola which differs by their immersed or semi-immersed yellow ascomata, ascospores without halo and their habitat of smooth bark (mainly Fagus) in humid and cold climates. Thelopsis gangwondoensis differs by its bigger semi-immersed ascomata (600–700µm in diam.), oblong halonate ascospores (8–12
x 6–8µm) and its habitat of smooth bark of deciduous trees. P. gyeongsangbukensis differs from its relatives within the genus in having 5-septate ascospores (22–26 x
6–8µm), semi-immersed, subglobose ascomata with a flattened top (250–400 µm) and a thin, matt, uneven gray-brown to gray-green continuous thallus without isidia. Key words: Key; Stictidaceae; Verrucariaceae; lichenized Ascomycota; Korea.