Objective: The purpose of this research was to aid creating an effective sizing system for the vacation wear intended for Jeju"s medical tourists, specifically females from the major countries including the USA, Japan, and Korea. Background: Medical tourism makes the gains of every year 40,000,000,000 dollar, every year 30% it is increasing. Thus the Jeju-do is propelling medical tourism. The body size each country is different. Consequently must set the body size standard for the women. Method: (1) It observed the body size of the Korean women of 2004 years and 2010 years. (2) It analyzed the body size of the women of the USA, China, Japan and Korea. (3) It set the sizing system of the women of the USA(ASTM), China (GB), Japan(JIS) and Korea(KS). Results: Korean adult females" height in 2010 has increased from 2004. The Waist Back Length, Waist Front Length, Arm Length etc has also increased along with the Height. The upper body has become slimmer at the same time; the Chest Circumference, Bust Circumference, and Underbust Circumference have decreased. The lower body on the other hand has become bigger: the Waist Circumference and Hip Circumference have increased. The BMI has decreased by 0.4 from 2004 - the Height has increased while Weight has decreased. The Chest Circumference and Under Bust Circumference of Korean women across all age groups have increased at a proportional rate to other parts of body; however, the rate of increase in Chest Circumference was far greater. American females(Caucasians) had the greatest ratio of waist to bust (Waist Circumference/Chest Circumference), smallest ratio of Neck Base Circumference to Bust Circumference (neck/bust). Korean females had smallest ratio of Waist Circumference to Underbust Circumference(waist/bust). As for the drop of Chest Circumference and Waist Circumference, American females had the highest and Koreans had the lowest. As for the drop of Hip Circumference and Chest Circumference, Japanese had the highest and Americans had the lowest, but Japanese women at the same time showed the A line body shapes. As for difference of Chest Circumference and Underbust Circumference, American females had the biggest(13.73) followed by Korean(11.1), Japanese(10.9) and Chinese(10.5). Conclusion: The women of the USA, China, Japan and Korea body size is different. Especially the value of the Bust Circumference - the Underbust Circumference is different. Thus, it set the sizing system(Table 8).