The purpose of this study was to investigate the development characteristics of Chinese college students' engagement during a service-learning project with a case study method: 273 reflective journals from 31 college students who participated in service-learning were analyzed. Results indicated that students' overall engagement showed 4 developmental stages: confusion and hesitancy, enlightenment and enthusiasm, fluctuation and adjustment, and stabilization and routinization. Also, the individual differences were investigated and demonstrated in following 3 categories: enthusiastic & fragile, regulatory & flexible, and persistent & resilient.