The purpose of this study was to investigate the cognitive mechanism of project-based learning teams of college students on the basis of the Shared Mental Model (SMM) theory. The study participants were 237 female college students in Korea organized into 51 project teams. To test the study hypotheses, a structural equation modeling was employed. The major study findings are as follows: (1) As hypothesized, member interaction was a strong predictor both for team-related and for task-related SMM. (2) The level of the team's division of labor reduced the member interactions. (3) Team-related and task-related SMMs were positively associated with team performance. The theoretical and practical implications based on these results are discussed.