This study analyzed the effect of individualism-collectivism propensity and social capital on participation activity as well as the effect of participation activity on fashion brands relationship orientation of social network service users. Also, this study investigated the difference in participation activity and fashion brands relationship orientation by participation level of social network service. A survey was conducted from October 1 to November 31, 2015, and 476 responses were used in the analysis. As results, the individualism-collectivism propensity was composed of vertical-horizontal individualism and vertical-horizontal collectivism. The social capital was composed of trust, norm, and network. Also, the participation activity was composed of personal interaction, consumer rights, information pursuit, interest pursuit, and economic pursuit. Vertical individualism positively affected information pursuit and economic pursuit, and horizontal individualism positively affected personal interaction, consumer rights, and information pursuit; in addition, vertical collectivism positively affected personal interaction, consumer rights, and interest pursuit. Horizontal collectivism positively affected information pursuit, but it negatively affected consumer rights. Consumer rights, information pursuit, interest pursuit, and economic pursuit of participation activity positively affected fashion brands relationship orientation. Also, there were significant differences in the participation activity and fashion brands relationship orientation by participation level. The study results provide useful information to the marketing strategies using social network service of fashion brands.