This study was analyzed and investigated to evaluate ecological distribution of medicinal plants in Miho Stream of Korea. Totality 463 taxa of vascular plants were appeared in lower part of Miho Stream. Medicinal plants were distributed 253 taxa, which were 54.6% of the total vascular plants appeared. Medicinal plants of official drug compendium(Korean pharmacopoeia) were 85 taxa. Medicinal plants were distributed most of the forest area, and followed field surrounding, stream surrounding and paddy surrounding respectively. The distribution of life form hemicryptophyte was the most frequent. Plant community of appearing area of medicinal plants was classified into Salix koreensis, Phragmites japonica, Echinochloa crusgalli, Artemisia selengensis, Miscanthus sacchariflorus, Setaria faberii, Panicum dichotomiflorum, Bidens frondosa, Humulus japonicus, Monochoria vaginalis var. plantaginea, Eleocharis kuroguwai, Erigeron acris, Pinus densiflora, Pinus rigida, Quercus acutissima, Quercus serrata, Robinia pseudoacacia and Castanea crenata community. Medicinal plants in plant communities that occur frequently were Humulus japonicus, Corylus heterophylla and Liriope spicata.