In this article, I will outline the practical and theoretical scope of the weblog, blogging and blogsphere. The weblog is the latest internet innovation in tandem with email and personal homepage. People who interact with their weblogs are known as bloggers. They do not only blog with their weblogs solely, but form thousands of communities within the cyberspace, which are now defined as the blogsphere. The weblog is firstly regarded as a personal publication system which challenges the existing media practice. And the most prominent weblog phenomenon might be that bloggers have successfully undermined the credibility of the mainstream press by their independent report of unexpected realities. However, with the fact that the weblog's population has sharply soared since its advent in 1997, the weblog has infiltrated diverse social domains. The weblog cannot be circumscribed to journalism entirely; rather, its influence has penetrated our ordinary life and has become part of our everyday experience. In this article, I will first set up the general agendas of weblog practice and introduce some distinctive weblog phenomena. Secondly, I will explain definitions of the weblog and blogging; then I will discuss the weblog's variety of utilizations and their theoretical implications following Carolyn Miller and Dawn Shepherd's (2004) categorization of weblogs. Finally, I will sketch an overall picture of the weblog research and discuss the possibility of a new research trajectory.