The dynamic of global economy drives the luxury fashion businesses to change. Offline stores are the primary retailing channelrnfor luxury fashion brand undergarments because luxury brands, through high quality, controlled distribution, and premium pricing, arernexpected to evoke exclusivity and uniqueness. Many luxury fashion brands find obstacles in maintaining their brand integrity while keepingrnup with the social media trend. Facebook is widely used as a marketing communication tool and marketing channel because visiting a luxuryrnfashion brand on Facebook may arouse consumers’ interest for shopping. The purpose of this research is to examine how a women’srnundergarments luxury fashion brand uses Facebook as a marketing system tool. This is done through observing the interaction between thernBrand and their customer by calculating the number of comments and fans page member, as well as the platform's accuracy of information.rnThe data analysis revealed that many women's undergarments luxury fashion brands promote their products and engage their customersrnthrough Facebook pages. The main problem for most of their Facebook pages was the old content. The findings of this study will be able tornforecast the future purchasing behaviour of luxury brands’ customers and guide to manage their marketing activities.