Manufacturing trends are gradually changing from mass production and mass consumption to "production of diverse products in small quantities". For this reason, design is recognized as an important element with which a customer judges value. In order to employ the designer's sensitivity and realize high quality designs, CAD systems which can carry out analysis evaluation of design properties quantitatively, and improve design based on the results is required. In the initial stage of designing, designers embody image form by repeating a sketch. In this process, if the form image of a sketch curve can be evaluated quantitatively and the design form image can be controlled based on the evaluation parameters, this will provide effective design support. In this research, we proposed parameters by which the image of sketch form can be evaluated quantitatively, and investigate the tendencies of various curves and curved surface form. We also developed a system which reconstructs design form using the proposed evaluation parameters.