Field surveys of Thrips palmi Karny on plants during winter seasons from 1995 to 1996 indicated that the thrips could overwinter as an adult stage on Jeju island, the southernmost island of Korea. In both years, overwintering T. palmi adults were collected after the coldest month (Jauary and Fevruary in 1995 and 1996, respectively), especially in the southerm part of the island. The thrips population was very high in december 1996(92.7% of total adults collected), then rapidly decreased from January through April, and slightly increased from May. T. palmi adults were collected from thirty wild plant species in fifteen families and from twelve winter crops in six families. On Stellaria media Vill and Artemisia princeps Pampan., T. palmi were continuously found during the whole winter season. They appeared to be important as overwintering hosts for T. palmi. Sex ratio of the thrips was extremely female bised(98.8%).