In recent years, instant messaging (IM) has become a popular medium of online communication. While IM is expanding into the enterprise beyond personal use, it brings the convenience and also doubts. IM possesses the instant feature which is even faster than email so to potentially reduce the cost of communication and increase the effectiveness of communication; while the doubts being surrounding the employees’ use of IM for personal chatting purpose which might reduce productivity. In the past, however, research on IM has been mostly on users such students or general Internet users with few addressing enterprise employees. This study focuses on enterprise organization and proposes a comprehensive model in which four aspects of social influence, perceived IM capability, computer self-efficacy, and task nonroutineness are integrated to explain the influence of IM usage in organization and to explore the relations between IM and organizational communication satisfaction. Three hundred ...