Abstract: Knowledge sharing, especially tacit knowledge sharing has significant impacts on the performance of team innovation, while there are few positive researches conducted on this subject. Based on the theoretical analysis and in-depth interview, a conceptual model on the correlation between postgraduate team knowledge sharing and its influencing factors is built, and six factors, namely, organizational leadership, organizational culture, knowledge sharing performance, cellectivism value, personal insecurity, and academci pressure are explored. Using the survey data and Structure Equation Model(SEM), the effects of these factors on graduate students’ tacit knowledge sharing behavior in postgraduate teams are studied; some suggestions for improving tacit knowledge sharing in postgraduate teams are presented at last.