Using monthly rainfalls, this study investigated outliers of annual and/or seasonal rainfall for quantitative assessment of historical droughts in Korea. Based on the analysis of annual rainfall, Icheon, Geochang, Jeongeup, Suncheon and Jangheung gaging stations were selected to represent the major river basins, because they had most frequent dry years. The overall results indicated that the years of 1988 and 1994 were the worst dry years. Although the 2001 drought was not severe, it resulted in typical agricultural drought damage mainly in Seomjin and Yeongsan river basin due to the lack of agricultural water. On the other hand, the droughts of 1981-1982 and 1994-1995 were long term nation wide droughts that lasted more than two years resulting in extensive drought damages to parts of the country.