Endophytic fungi were isolated from the leaves of diverse plants inhabiting Jeju Island, Korea. The fungal isolates were identified through phylogenetic analyses incorporating nucleotide sequences derived from the internal transcribed spacer region, large subunit region of ribosomal DNA, and beta-tubulin gene. Our results identified six endophytic fungi previously unknown in Korea namely, Diaporthe goulteri, Diaporthe vaccini, Rhizosphaera pini, Valsa friesii, Xylaria primorskensis, and Zalerion arboricola were identified. Here, we present their cultural and morphological characteristics and phylogenetic relationship.