This research focuses on the media capabilities by comparing traditional media and mobile media. Previous studies have examined media capability and its impacts on communication performances. Media richness theory(MRT) and media synchronicity theory(MST) are representative framework in this area. However, little research has investigated communicators’ perception on media’s capability and synchronicity and how they affect communicators’ satisfaction and communication performance. This study argues that communicators’ perception about media, as well as actual capabilities of the media will affect communicators’ use of media and media’s effectiveness. The effectiveness of the media will also affect communicators’ satisfaction and group cohesiveness. An experiment was designed and conducted with a total of 313 college students and MBA students in South Korea and the U.S. Subjects were required to perform a group collaboration task using Twitter on either PC or mobile phone. Subjects worked on an experimental task in teams of four people. After experiment was completed, subjects were asked to answer a postexperimental questionnaire which was designed to measure subjects’ perceived media capability (transmission velocity, immediacy of feedback, parallelism, rehearsability, and reprocessability), satisfaction, and group cohesiveness. The results show that the type of media(PC and mobile device) does not significantly affect people’s perceived media capabilities. It implies that capability of a medium lies more on communicators’ perception and how they use the medium rather than physical attributes of the medium. It was found that the immediacy of feedback, parallelism, and reprocessability have positive influences on the communication satisfaction. The enhanced satisfaction also increases the group cohesion. This research empirically analyzed the key factors of media capabilities for communication satisfaction by verifying Media synchronicity theory in the group collaboration context.