: Among Internet applications, blogs are known for its exponential growth in recent years. Blogs can be viewed as a kind of information system which people used to communicate with others. While past studies placed focuses on blogger’s motivations to use blog or potential applications of blogs, relatively little research has been conducted to investigate the relationship between effects of blog system quality and social influence on bloggers’ usage intention. From the technical and social views, this study proposed a conceptual framework involving IS qualities and social influence. 613 responses were collected via web survey. Results show that information quality, system quality and blogging function quality positively influence bloggers’ usage intention. Moreover, social influence significantly affects bloggers’ usage intention directly and indirectly