Rhodophyta is one of major groups in the number of species and diversity of the marine algal flora. The occurrence of Korean 5 red algal species is reported for the first time on the list of Korean marine algal flora based on morphology: Ceramium pacificum, Cumathanmnion serrulatum, Gayliella fimbriata, Leptofauchea rhodymenioides, Sorella pulchra. Ceramium pacificum from Korea is recognized by complete cortication, many adventitious branches in a radial arrangement, 7-8 periaxial cells, and plant length of 1-2 cm. Cumathanmnion serrulatum is characterized by cartilaginous single main axis with a prominent midrib, serrulate blade, many higher orders of bladelets on each blade, and tetrasporagia produced near the midrib acropetally and then outwardly. Gayliella fimbriata is featured by clavate gland cell and 5-7 periaxial cells. Leptofauchea rhodymenioides is characterized by erect with flattened, dichotomously branched fronds, 1-2 cortical cells loosely arranged, 2-3 cell medullar layers with large colourless cells. Sorella pulchrais recognized by short branches produced alternately pinnate manner from margins of axial, mostly polystromatic frond, and tetrasporangial sori on the center of branches.