The distribution of C_# and C_4 type plants in Korea were studied. In the standpoint of photosynthetic types, plant distribution in Korea is classified as C_3 and C_4 type plant zones. The forest destroyed by man interference, cultivating areas, and seashore areas are characterized by the dominant of C_4 type plants. (Figs. 2, 3, 4, 5) According to the results of this study, C_3 and C_4 type plant distribution in Korea has a great relation to the habitat of plant vegetation(Table 1). The arid areas were in high proportion of C_4 flora percentages, while the well-developed woody forests or the vegetation of humid areas were in lower proportion(Fig. 8).