This article is a meta-theoretical study of the ''public sphere" and ''Publicness" (=?ffentlichkeit) in the information age. Almost all studies of the Publicness (or. public sphere) have modernism or modernity as a context. However I suggest that，in the information age，public sphere studies must stress the context of postmodernity. As is generally known，the agenda of publicness (or public sphere)，which is one of the most actual themes of the contemporary Information Society，origimates from critical theorists such as Habermas and Alento. In particular, the impact of Jurgen Habermas (the central figure of the second generation of Frankfort school) is very strong，so，studies of the public sphere are regarded as being one of the modernism theories. Since the Intemet-age has began，Postmodern theory has been important in the ''grown up" Information Society，with many potential applications of Internet-communication being indicated by postmodern theorists. The theorists have also indicated many problems in the information age，but they have not proposed any altematives. On the other hand，public sphere studies have been criticized concerning the reality of their communication theory. Perhaps this criticism of their theoretical strategy is justified. Indeed，their concept of ''communicative action" is too idealistic，so they cannot grasp the reality of media-mediate communication. However，the construction of the public sphere is an actual altemative in the information age. In this article, I try to set up a hypothesis about the relation between post-modernity concerning media-mediate communication and the public sphere, by connecting post-modern communication studies (e.g. analiysis of frendship and relationship s in youth culture studies) and info-public sphere theories.