The purpose of this study is to develop Blue-Jean Design for Ideal Body Shape. The final aim of Fashion design is looks beauty of people by optical illusion. This study is based on Gestalt therapy and, is blue jeans design using optical illusion of vertical line for ideal beauty body image. Optical illusion for blue-jean design effect to achieve the ideal body shape. We can accumulate the preceding study for modern clothing from design and the related optical illusion effects. Vertical line stitches have all the advantages especially in pants design. I design blue jeans using optical illusion theory. The results of this study are as follows: First, Vertical line helps that jean has the long body shape effectively. Second, Jeans which have two or more vertical lines is more effective than simple Jean in order to make slim body shape. Third, Appropriate position of horizontal lines can be effective to make long body shape. Fourth, Top stitch, pin-tuck and pleats can be applied to vertical or horizontal lines instead of cutting lines.