From traditional ceremony to science technology, origami was used as technique for artistic creativity and functionality based on formative characteristics. The purpose of this study is to analyze the expressive characteristics of functionality in fashion design using origami technique. The method of this study was to analyze recent documentaries, fashion books, fashion magazines, internet web site and so forth. The results were as follows: In various fields of design, the category of the expressive characteristics was classified as efficient correspondence of space, compositive convergence of function, variable potentiality of form and human ergonomic optimum. In recent origami fashion based on functionality, the efficient correspondence of space was expressed constructive or decorative pocket design, using on clothing surface and varied design by lifestyle. The compositive convergence of function was expressed innovative connection of fashion items or non-fashion items and deconstructed classical clothing pattern. The variable potentiality of form was expressed control of form by irregular fold, dynamic metamorphosis by organic fold and creation of varied clothing silhouette. The human ergonomic optimum was expressed metamorphosis mechanism from two dimension to three dimension, suitable construction to physical ability and limit and organic form based on articular folding. The functional origami fashion means reflection of nomadic lifestyle, maximum of usability, pursuit of playful sensibility, creation of new body aesthetic and pursuit of technology and humanism. And the result of these study may be used for creative inspiration in fashion design because of unique characteristics.