Benthic marine algae of Shinjido located on the southern coast of Korea have been investigated to know the floristic composition and community structure. The study was conducted from the intertidal to subtidal zones at two different locations (Kangdok and Donggori) using a line transect method from January to October, 1994. A total of 120 species of marine algae were identified, and they includes 15 green algae, 31 brown algae and 74 red algae. Of these, 87 and 104 species of marine algae occurred at Kangdok and Donggori, respectively. Algal vegetations were divided into three different zonations: the upper, the middle and the lower zones. The representative species are Enteromorpha compressa, Ulva pertusa, Porphyra suborbiculata, lshige okamurae in the upper zone; Hizikia fusiformis, Sargassum thunbergii, Gigatina intermedia, Corallina pilulifera in the middle zone; Pachymeniopsis elliptica, Gelidium amansii, Sargassum horneri in the lower zone. In terms of biomass the dominant species were U. pertusa, I. okamurae, H. fusiformis, C. thunbergii, C. pilulifera, C. amansii, C. tenella. The flora could be classified into six functional form groups such as the coarsely branched form $(36.7\%)$ the filamentous form $(27.5\%)$, the sheet form $(15.8\%)$, the thick leathery form $(10.0\%)$, the jointed calcarious form $(5.0\%)$ and the crustose form $(5.0\%)$.