One new species of the family Comesomatidae Filiepjev, 1918 was collected from marine sediments in the South China Sea, and it is described here as Setosabatieria minor sp. nov. Setosabatieria minor sp. nov. is characterized by its relatively small body size in the genus, mutispiral amphideal fovea with 3 turns, four longitudinal rows of 2-4 cervical setae, 8 minute pre-cloacal supplements, short and blunt spicule with a central cuticularized strip and gubernaculum with a small dorso-caudal apophysis. The new species is similar to S. australis Leduc & Gwyther, 2008 in having relatively small body size, few cervical setae (2-5) per file and few precloacal supplements (7-9). However, the new species differs from S. australis by shorter spicule slightly arcuated with a short central cuticularized strip (spicules 30-31 µm vs 45-51 µm, Lshaped
with a median hollow region) and shorter gubernacular apophysis (10 µm vs 20 µm). Dichotomous key and pictorial identification keys to all known species of Setosabatieria are provided.