Dinetia decraemerae n. sp., a new species of the family Draconematidae, is described. This new species was collected from subtidal coarse sediments and small logs from the eastern coast of Korea. Dinetia decraemerae n. sp. is distinguished from D. nycterobia and D. orientalis by the following combination of characters: number of cephalic adhesion tubes (34-36 in male and 32-34 in female), number of sublateral posterior adhesion tubes (7-8 in male and 12-13 in female) and subventral posterior adhesion tubes (16-20 in male and 17-19 in female), the buccal cavity (narrow and armed with a dorsal and two minute ventrosublateral teeth), the body striation (not completely surrounding the unispiral amphidial fovea), large, slightly curved, spicules, gubernacular apparatus paired with distal lateral enlargement of the corpus extending around distal part of each spicule, and C′ value (2.6-2.9 in male and 3.4-3.8 in female). The generic diagnosis is emended and a key to species provided.