Five naturalized species of taxa in Jeju such as Solanum ciliatum, Rubus fruticosus, Lepidium bonariens, Rudbeckia hirta, Solanum photeinocarpum have been found and given the Korea names. Among those species, four species such as Solanum ciliatum, Rubus fruticosus, Lepidium bonariense, Rudbeckia hirta, Solanum photeinocarpum. are naturalized in Korea but have not been reported yet and Rudbeckia hirta has been cultivated as a garden plant on the mainland Korea but it is found in the natural environment on Jeju island in Korea. And so we report here that Rudbeckia hirta is a naturalized species.