Abstract: Transactive memory system (TMS), a cooperative labor division developed in communication processes among team members, can be simply defined as a shared cognition about "who knows what". A TMS coordinates knowledge and expertise among team members, consequently enhances knowledge integration and sharing. Firstly, this paper reviews the definitions about TMS and virtual teams. Secondly, TMS formation and effectiveness, and the relation with team virtuality are highlighted. Lastly, it is suggested that more future work should be put on team inputs, team outcomes and moderators of team performance, by taking IT adaptation, research methods and context into consideration.

Key words: transactive memory system, virtual team, virtuality, knowledge management, team inputs, team outputs