Coastal Bryothinusa Casey, the most species rich genus among all the coastal aleocharine genera, contains 30 species worldwide. Members of Bryothinusa occur along the coasts of the Pacific and Indian Oceans including their neighboring seas. In Korea, four species were recorded from the western and southern coasts of the Korean Peninsula by Ahn and Jeon and most species are found mainly under stones, seaweeds, and debris on mud flats and sandy beaches. While studying the Korean coastal Staphylinidae, we have accumulated sufficient specimens of Bryothinusa species that look different with the known species previously. After examining the specimens thoroughly, we identified them as two new species including one species new to the Korean fauna. They correspond well to the diagnostic characters of Bryothinusa: body parallel-sided; labrum as long as wide; mandible elongate; lacinia with setae interdigitating with spinose scales; lacinia and galea remarkably elongate; ligula short, not divided; anterior angles of mentum prolonged into spinose processes, two long medial setae present on mentum; mesocoxal cavities very closed, not margined posteriorly; mesoventral process sharply pointed; tarsal formula 4-4-5; apical lobe of paramere long. A total of seven species including two new species and one species newly recorded in Korea are recognized. Here, we describe two new species (B. brevipennis and B. littoralis) with illustrations of diagnostic characters, compare the new species with related species, and report B. algarum Sawada for the first time in Korea.