The floods of Korea happens periodically during summer. The cause of heavy rain that provokes floods can be classified into typhoon and localized downpour. The typhoon happens in the tropical region. It causes one of the worst damage to Korea by extreme rainfall and strong wind. Usually, it is known that the flood damage by the typhoon is larger than that by the localized downpour. Therefore, this study classified rainfall events into typhoon events and localized downpour events based on the cause. Through statistical analyses of the rainfall data, this study investigated special quality of the rainfall during the time of typhoon. In analysis results, probability Precipitation calculated by the typhoon events were exposed bigger than that calculated by all rainfall events.