OBJECTIVES: The purpose of this study was to examine the associations between physical activity (PA), physical fitness, and two potential factors of exercise behaviors of self-efficacy and the processes of change in College students. METHODS: Using campus e-bulletin, one hundred and twenty-seven undergraduates were recruited from University of Macau. Physical fitness tests including body fatness, grip strength, sit-ups, push-ups, sit-and-reach and step-test, and questionnaire survey to investigate self-reported physical activity (physical activity rating scale 3, PARS-3), self-efficacy and the behavior process were conducted. RESULTS: The higher self-reported PA, the more sit-ups. Moderate correlations were found among PA, self-efficacy and the behavior process (r = 0.46 - 0.61, P<0.01) in male students. CONCLUSION: For male college students, self-efficacy and exercise behavior process were associated with self-reported PA. Sit-up might be good indicator of physical fitness to differ self-reported PA. There were no such findings in female college students.