This study was conducted to compare the community structure and biodiversity of ground-dwelling invertebrates between conventional and organic paddy fields’s levees. Ground-dwelling invertebrates were collected using a pitfall trap every month for two years (2010-2011) in levees of conventional and organic paddy fields. The numbers of species and individuals were higher in organic paddy field than in conventional paddy field. For the pests, the treatment of insecticide and herbicide reduced the number of Delphacidae, and Chrysomelidae, but did not affect the other pests such as Chronomidae, Culicidae, Thripidae, and Aphididae. For the natural enemies, the treatment reduced the number of individuals of most of enemy's taxon (except only one taxonomic group, Ichneumonidae) in the levee of conventional paddy field.

In order to evaluation of beneficial functions for organic farming, we have divided beneficial functions as 9 sub-functions such as flooding control, fostering water resources, purifying the air, mitigating summer climate, purifying water quality, decreasing soil erosion, accumulating soil carbon, conserving biodiversity, and preventing accidents from pesticides. And they were quantified by searching related repots and statistics, and surveying fields. Organic farming, especially organic paddy farming, showed that some functions like fostering water resources, accumulating soil carbon, conserving biodiversity, and preventing accidents from pesticides were higher than conventional paddy farming, while the others were almost similaι The foste꺼ng water resources function was evaluated as 4,297 ton ha-1 year-1 to increase about 3.6% comparing with that of conventional farming. New function for accumulating soil carbon at organic paddy fields has been assessed by 4.67 ton ha-1 in terms of long periods over 10 years. Considering area of organic paddy farming in Korea and value of carbon price， it was evaluated monetary value as 22.4 to 84.1 billion won using replaced method. It could be also evaluated that flooding control, fostering water resources, purifying the air, mitigating summer climate, purifying water quality, decreasing soil erosion, and preventing accidents from pesticides were 2,980, 123.4, 482.6, 87.5, 0.9, 55.6, and 284.1 billion won, respectively. Conserving biodiversity function would be very big at organic farming though it couldn ’l be evaluated as monetary value.