The purpose of this study to present updated regional annual mean rainfall erosivity data in the Republic of Korea. In 2012, Ministry of Environment in Korea published the notice about investigation and survey procedure for the amount of topsoil erosion and adopted USLE (Universal Soil Loss Equation) model to predict the amount of national-scale soil erosion in Korea. In the notice, regional rainfall erosivity values for 158 sites, which is essential to apply the USLE, were included, however, these values came from the data made before 1997 and need to be updated. This study collected, classified and combined annual mean rainfall erosivity data from the literature review to analyze the data. We presented that new iso-erodent map, interpolated by IDW (Inverse Distance Weighted) method and extracted updated regional annual mean rainfall erosivity data at 167 regions for 1961~2015. These values will be used as updated rainfall erosivity data to predict the amount of topsoil erosion in Korea.