This study aims to examine for efficient production methods of custom-tailored clothing and application of 3D virtual clothing system in custom-tailored clothing market, by producing and analyzing both real clothing and 3D virtual clothing. For this study, a middle-aged woman is selected as the subject figure and one-piece is selected as the experimental clothes item. In real clothing, I conducted the wearing evaluation for experts and the subject figure. And In the virtual clothing, I conducted the wearing evaluation with i-Designer using 3D virtual clothing on simulation program. There are some differences between the data from body scanning and the real body size. In the custom-tailored clothing market in which the fitness is important, the research which measures the more exact data is needed. And in the case of complicate design, the functions which measure the activity and the fitness variously and correct the parts of curves are needed. This study experiments the availability of application of 3D Virtual Clothing System in custom-tailored clothing market by selecting one-piece as the experimental clothes item. So the follow-up studies for the other designs and fabrics are needed. Also, if the studies for checking the clothes pressure, the amount of composure, the space between skin and clothing when the virtual model wearing clothes is walking or shaking his arms are proceeding, then 3D virtual clothing System is applicable in custom-tailored clothing market. But there are some restrictions and lack of education in virtual clothing System yet, and it makes hard for workers in clothing market to use it in real production. However, 3D virtual clothing System will be practical in real market if there would be more research on its usability and practicality, and workers in clothing market can be easily educated on techniques of 3D virtual clothing system.