In present modern society, media contributes more to the constructing of personal identities than any other medium. Music video, a postmodernism branch among a variety of media, offers a complex experience of sounds combined with visual images. In particular. fashion in music video helps conveying contexts effectively and functions as a medium of immediate communication by visual effect. Considering the socio-cultural effects of music video. gender identity represented in fashion in it can be of great importance. Therefore, this study is geared to the reconsidering of gender identity represented through costumes in music video by analyzing fashions in it. Gender identity in socio-cultural category is classified as masculinity, femininity, and the third sex. By examining fashions based on the classification. this study will help to create new design concepts and to understand gender identity in fashion. The results of this study are as follows: First. masculinity in music video fashion was categorized into stereotyped masculinity, sexual masculinity. and metro sexual masculinity. Second, femininity in music video fashion was categorized into stereotyped femininity. sexual femininity, and contra sexual femininity. Third, the third sex in music video fashion was categorized into transvestism, masculinization of female, and feminization of male. This phenomenon is presented into music videos through females in male attire and males in female attire. Through this research, gender identity represented in fashion of music video was demonstrated, and the importance of the relationship between representation of identity through fashion and socio-cultural environment was reconfirmed.