Heterotrichous ciliates were isolated from marine and brackish habitats in Korea, and their morphology, infraciliature and morphometrical characters were investigated using silver impregnated methods. These three Condylostoma species were identified as Condylostoma curva Burkovsky, 1970, C. minutum Bullington, 1940 and C. spatiosum Ozaki and Yagiu in Yagiu, 1944. The species of Condylostoma based on morphology are highly variable in most of characters and distinguished as following. Condylostoma curva is oval to elongate ellipsoidal, size about $245{ imes}100{mu}m$ in vivo, and conspicuously dark greenish brown with cortical granules on their surface, buccal cavity relatively large about 40% of body length, 5-11 macronuclear nodules, 4-8 frontal cirri serially arranged and 22-38 somatic kineties. Condylostoma minutum is elongate ellipsoidal and the size about $310{ imes}55{mu}m$ in vivo, buccal field about 35% of body length, 12-20 macronuclear nodules, adoral zone consisted of 82-107 membranelles, large and long one frontal cirrus and 38-44 somatic kineties. Condylostoma spatiosum is large elongate ellipsoidal, size about $670{ imes}105{mu}m$ in vivo, buccal cavity about 25% of body length, 11-25 macronuclear nodules, 111-144 adoral membranelles, membrane-like 2 frontal cirri, 49-74 somatic kineties. These three Condylostoma species are described here for the first time in Korea.