This paper is aimed at exploring those theories and their applications which have traditionally adopted to investigate offshore outsourcing practice. Contemporary research in knowledge transfer concerning outsourcing software development context between partners, whose goals are conflict, has adopted several theories in information system (IS) disciplines. Several relevant IS theories have been being adopted in the IS outsourcing literature. However, social exchange theory (SET) has a unique explanatory power. In the discussion, the traditional IS theories will be examined, and the potential of the SET will be explored.