This paper is a perspectiveon the reformative costume expressed by Gustav Klimt who led the Secession Movement as a great master in Vienna. Klimt actively expressed a new costume style in his paintings, which influenced heavily on the modern costume design. This paper may contribute to reestablish the constructive direction for the 21st century fashion design based on Klimt's pursuing holistic art concept. The reformative costume in Klimt's paintings has two characteristics; ornamentism, eroticism, and reformativeness. Ornamentism is expressed with fantastic colors, various motives, exotic features, simple style clothes, and so on. Klimt used independent ornaments to express carnal desires metaphorically, which set ornaments free to lead spectators to the dreamy or elusive state and even have spectators indulged in ecstasy. As the Secession Movement focused on reforming all areas of life artistically, the costumes of Klimt's paintings symbolically express the reformativeness; he portrayed the woman in the early 20th century and sought to reform its contemporary value as a visual sensuality. Klimt tried to disrupt from the former era by over-emphasizing eroticism. The erotic expression with the colors and the style of ornaments substitute naturally for suggestive eroticism of the feminine body. With has creativity, Klimt has spectators extract the various senses from the female image in his paintings. Klimt's creative spirit on the holistic art concept could be helpful to develop a unique design as a catalyst foreseeing over the present.