One of the sapstain fungal species isolated from the stained sapwood of a Japanese black pine in Korea was characterized. The fungal species is tolerant to cycloheximide and has Petosum-like synnema and Sporothrix type synanamorph which are found in the anamorphs of the Ophiostoma piceae complex group. But the species could not form perithecia on MEA. Based on cultural and morphological properties and analysis of the β-tubulin gene sequence, the fungal species was identified as Ophiostoma quercus. Here, we report mycological characteristics of the anamorphic stage of Ophiostoma quercus isolated in Korea.