This thesis is an ethnographic study which investigates the production and consumption practices of online journalism in Taiwan. Two key questions are asked: how is online journalism practised in the domain of production and consumption and how is online news culture shaped or constituted through these practices? Distinct from existing studies of online news, I argue that online journalism should be studied as an emerging cultural form, rather than a subordinate of any existing forms of news media. My ethnographic study focuses on the practice aspect of online news consumption and production. It includes observation of, and interviews with, both professional news-workers in the online newsroom and online news consumers in private spaces. The analysis of this data reveals that online journalism has formed a 'convergence news culture'. This convergence culture in online journalism does not only involve an integration of different media formats and organizations, but also involves a convergence of different practices conducted by dispersed participants relating to online news media. In showing how the convergence culture of online journalism is constituted and shaped, I frame the analysis of online journalism through three interrelated aspects: online news production, consumption and online participatory journalism. My key finding suggests that online media, influenced by the convergence of different practices, shapes and expands the producer/consumer relationship. This relationship, therefore, cannot be captured by the conventional dichotomy of information provider - recipient. Both professional news-workers, and consumers/citizens who are involved with the practices of grassroots/citizen journalism, contribute to the circulation of online news information via their various practices of online news media. A significant influence of convergence news culture and the changing relationship is that consumers' or citizens' online news practices have challenged the traditional mainstream definition of what journalism is, as well as provided different 'public knowledge' and perspectives to facilitate public discussions in a new, emergent online public sphere.