Mitrula paludosa (Geoglossaccae, Helotiales, Ascomycetes) is reported about morphological and ecological characteristics for the first time in Korea. The mushroom fruited on rotten pine leaves or fine twigs in ditches with flowing or standing water in Sogri Mountain National Park from May to June. The apothecium of M. paludosa is 20 to 50 mm tall. The cap is bright yellow to orange, cylindrical to wrinkled ovoid and 5~10 × 10~20 mm. The stem is whitish and cylindrical distinctly set off from the cap. The ascospore is hyaline, smooth long elliptical fusoid with round ends and 13~17 × 1.5~2.0 μm. The ascus is unitunicate, 90~110 × 5~6 μm, and has eight spores biseriately lined to the inoperculate apex. Paraphyses are septate filiform, 95~120 × 1.0-1.5 μm, 7~10 μm longer than the asci.