This research is aimed at identifying the factors affecting teachers' behavior in sharing knowledge in universities. Survey data were collectedfrom 422 teachers of six universities in Ho Chi Minh city. The research model is based on the Social Exchange (Homans 1958
Blau 1964), Social cognition (Bandura 1989), Cognitive development (Piaget 1965), Social construction theory (Jonassen & ctg 1995): and other previous studies. The reliability and validity of the scale were tested by Cronbach s alpha coefficient and exploratory factor analysis (EFA). The results of multiple regression analysis show that the five factors in descending order affecting the teachers' knowledge-sharing behavior in the universities are as follows: reward system, organizational culture, information technology, trust, learning orientation.