Two copepod species of Leptocaris belonging to the family Darcythompsoniidae are recorded from sandy mud sediments of salt marshes in South Korea: L. brevicornis (van Douwe, 1905) and L. trisetosus pacificus n. ssp. The genus Leptocaris is newly known from Korea. Leptocaris trisetosus pacificus differs from the nominate subspecies in exhibiting a sexual dimorphism in setal armature of leg 3, that is, bearing an additional seta on the second endopodal segment of leg 3 in male and an allopatric geographical distribution. This paper deals with the description and systematic accounts of them with detailed illustrations.