This study was attempted to investigate the possibilities of fitness evaluation of virtual model using 3D clothes modeling software. For the purpose, two one-piece dresses were made with two kinds of patterns using Qualoth program, and then each dress was fitted to a real model and a virtual model, and the results were compared and discussed. The result of this study was as follows. First, the fitness evaluation of real model showed a significant difference only at a little difference in figures (1-2.5cm) of the pattern, while any significant difference in appearance was not found in case of a virtual model fitted a dress made out of a pattern with the same difference in figures. Second, items to evaluate a difference in patterns using 3D clothes modeling software were shoulder line, the distance between shoulder points, armhole line, ease of armscye depth, and overall appearance. Because all the items fall under design lines which make up outer lines of a cloth, it can be said that the Qualoth program is good for representing design, rather than exposing a small difference in patterns.