Macroinvertebrates were examined to elucidate community structures of a total of 5 rice paddy types, Korea. A total of 67 species were found in the study sites. Generally, macroinvertebrates were dominated by Pomacea canaliculata. Limnodrilus gotoi, Ephydridae sp. in organic rice field. Also, aquatic insects were dominated by Diptera, which constituted 25% (17 species) of the total number of species collected. The diversity of macroinvertebrate in several organic rice paddies was higher than that of conventional rice field. The organic rice paddy and nonpesticide agricultural area were also diverse. Samplings were used to detect the influence of farming activities on macroinvertebrate community variation. The study indicated that studied sites showed difference in their macroinvertebrate composition, and these differences are strongly related to differences in habitat quality and microhabitats.