Information Effluence leaks are caused by the wide use of the P2P program in Japan and Korea lead by the increase of internet use and network infrastructure expansion. This research confirms the seriousness of the data collected from the P2P leaks of the two countries and furthers its study by researching how countermeasures are applied. The effectiveness is verified by collecting data according to countermeasure applied periods. Both countries had information leaks, but in the case of Japan, not only personal information leaks but corporation, administrative agency, military, and others in a wide range as well. As a countermeasure against information effluence, Korea is enforcing counter plans mainly against the P2P service businesses and for Japan, various plans are taken such as business guides for each agency, organization management, SW development and supply, HW supply, and ect. The leaks in Japan were more severe than the ones in Korea but they had well planned countermeasures that were applied. Therefore if the Japanese countermeasure on information effluence of P2P programs is taken as a lesson, Korea can prevent the problem of leaks beforehand.