The purpose of this study is proposing a knitting method that is suitable for the bodies of women in their 20's and can enhance aesthetic aspect and wearing satisfaction. For this study, four kinds of seamless knit one-pieces were implemented by different knitting method of waist dart each other. The inspection of the exterior and the sensory test of movement adaptability were included in this study. The results of this study were listed below. Exterior evaluation of the four samples results that the sample with outside narrowing and widening get low grade. Thus, we can see that the method having only outside narrowing and widening for waist shaping can cause problems. In addition to that, the sample with inside narrowing and widening get highest grade for almost all test items. The dressing evaluation results that the knitting method of waist dart affect only on the exterior but not on the movement adaptability of the seamless knit one-piece.