This study aims to explore the effectiveness of college service-learning curriculum and the related factors that influence the students' cognition about service-learning. The participants were 501 students of a medical university in southern Taiwan. Data was obtained through questionnaire survey. The results showed that: 1. After finishing the pre-service preparation semester, more than 70% of the students thought their understanding of the goals of service-learning curriculum reached 75% degree and above. 2. During the field service semester, more than 60% of the students thought themselves reached 100% degree of devotion in agency services. 3. About 80% of the students thought themselves reached more than 75% degree of improvement in the willingness to serve others. 4. Overall speaking, the students' cognition about service-learning didn’t have significant changes after the agency services. 5. The factors that influences the students' cognition about service-learning were found including: degree of devotion in agency services and the assistance from the agency members. Hopefully, the conclusions of this study can serve as a useful reference for instructors of service-learning curriculum for research or teaching purposes.