The lantern fly, Lycorma delicatula (White), was firstly introduced at least around ten years ago in the Korean Peninsula, and is now distributed throughout the mainland. We collected 37 L. delicatula isolates, totally 762 individuals from various locations in Korea, China, and Japan. Our results, based on molecular comparison showed multiple introductions of L. delicatula into Korea from China as followed; 1) The population which was spreaded and prevalent in a wide area after 2008 was identical to that of Shanghi, suggesting that main routes was the seedlings of Ailanthus altissima imported a few times from Shanghi into Incheon port in 2004~2005. 2) The populations in Changwon and Samcheok collected in 2011 were from Beijing and Tianjin, respectively. 3) The population in Cheonan collected in 2006 was different from other populations.