The purpose of this study is to explore the aesthetic characteristics of outerization phenomenon of contemporary fashion. Outerization, transforming underwear as outerwear, is one of the most dominant and widespread fashion trends in the dawning of new millenium. Fashion always exists for living body and tributes to express idealized beauty of human body and aesthetics of the era. If so, exploring the formative expressions and aesthetic characteristics of outerization would be an meaningful guideline to deduce changed relationship between fashion and body of the 21st century. The methodology of this study is to research of fashion collections such as Paris, Milan and New York which were held the first decade of new millenium, from 2000 Spring/Summer to 2009 Spring/Summer. The styles expressing outerization were selected and assorted based on the main formative expression. Then the aesthetic characteristics were classified. The way of expression of outerization is categorized into 4 parts ; Transition, Exposure, Transparency, and Deconstruction. Aesthetic Characters of outerization is classified 4 assortments as well ; Eroticism, Fun with parody and kitch, cyber culture, Gender politics, and Power fetish. Eroticism is the most clearly identified one. Coming out of underwear imply naked body itself, so it has erotic appeal. Fun is the second character. A pleasant sensation from the outerization of undergarments maximizes a disposition of play from parody, kitch, and cyber culture. The third is Gender Politics and it introspects how the society consumes woman body in history and modern times. Power Fetish, the last one, speaks for the female body with changed vision for femininity underneath the sphere of influence of feminism and post modernism, then emphasizes the subjectivity and independence of woman. From the research above, this study will help to understand the overwhelming outerization phenomenon and contribute to expansion of the horizon of the study of fashion aesthetics. It will serve fashion creative source through various outerization cases as well.