Abstract
When register social media services, users are able to choose their screen name. Some services require user's real name which generally means legal name, however, in the context of “social networking", some users use their birth name or working name. This paper focuses on married users who use both legal and birth name in their daily life then try to examine how they behave on social media. As a result of our online survey, for example, half of 20's women put on their maiden name only instead of putting both surnames.