The purpose of this study is to experiment and develop seamless-effect knitwear design using tubular-jacquard structure in order to find a new method of manufacturing knitwear and to suggest a new design. The study is based on changing the point of view about using the practical technique like the tubular jacquard which has been used mainly for expressing patterns. The result of experimenting this, a piece of fabric is able to being worn as a piece of garment. As for using circular structure of tubular jacquard, a body can be fitted into the big space between front and back part of fabric and seams can be made of small patterns of jacquard fabric. The silhouette, the drape and the result of the garment of this experiment are different from the ordinary outfit. Therefore, the study to find a new way of design and manufacturing should go on to suggest a different form and method.