Regional variations of Dictyostelid cellular slime molds were examined using molecular data. The intertranscribed spacer regions including the 5.8S ribosomal DNA of 2 species(D. purpureum, P. violaceum) of Cellular Slime Molds were sequenced and analyzed. Among 13 strains of D. purpureum and 12 strains of P. violaceum analyzed, each two strains were obtained from ATCC and the others were isolated from the forest soils in Korea. The sequences of the 5.8S ribosomal DNA were conserved among the strains of the same species, but unexpectedly highly variable among species. A high level of genetic diversity was found which was best resolved at the genus/species level as well as the family level by sequence data from the ITS 1 and ITS 2 regions. According to the sequence alignments by CLUSTAL X and the phylogeographic analyses by PAUP, 12 strains of P. violaceum were divided into three groups among which there were no difference of the morphological characteristics. Among 13 strains of D. purpureum, genetic variations were related to two morphological types, the temperate and subtropical type. There was no variation pattern according to geography in Korea, but there were some variations between Korea and other countries.