This study aims to investigate Taiwan youths' behavior on Facebook via using an Internet survey. According to previous studies, users on Facebook tended to disclose and share themselves, interact with friends, play games, or use applications. Factor Analysis allowed the researchers to analyze and confirm that Facebook users have multiple using behaviors. Furthermore, this study simulated a marketing strategy planning situation, and used a two-stage clustering approach to analyze three segmented groups: Friends-caring, Self-promoting and Games-sharing. Finally this study suggests a more plausible and effective market segmentation strategy for study on Facebook by marketers and future researchers.