Korea is a country which currently suffers from water shortages. It is expected in the early 21st century that Korea's water shortage will be more than 10% of the annual demand. The water shortage problem is more serious in the coastal areas where many industrial complexes are located. To solve the water shortage problem, seawater desalination gets more attention as an alternative water supply source since Korea is surrounded by seawater on along three sides of the nation's borders. For the potential application of seawater desalination in Korea, this economic analysis was conducted using cost data for plants in the Middle East, the United States, and other countries. This study is to provide a basis for the government to establish a strategy for using seawater desalination in Korea. This analysis discusses how economic the RO process is compared to the thermal processes of MSF and ME, especially in cases where the capacity is less than about 50,000 ton/d. In addition, the largest obstacle to the application, the low water charge in Korea, is discussed. The unit cost of the RO seawater is also analyzed to be about $1.35/t at 1990 prices. As a conservative estimate, this unit cost is assumed for the RO application in Korea which seems possible early in the 21st century. In 1995 the average tapwater charges in Korea's coastal areas was $0.53/t at the 1990 price. If the water charges are raised at an annual rate of 8.9%, it will become $1.35/t by 2006 and the RO desalination is able to be widely applied for dealing with a severe water shortage expected. Since the desalination plant can be operated regardless of weather conditions, industries In Korea's coastal areas which suffer from frequent droughts and water shortages will look into this option with more attention.