While John Dewey's learning theory has been widely credited as the essential theoretical underpinnings of service learning, lesser attention has been paid to his concept of moral imagination regarding its immense potentials in nurturing college students' moral growth in service learning. This article explores Dewey's framework of moral imagination and its implications for moral education in college service-learning programs to construct a moral imagination model that could enrich current service-learning theory and practice. The key components and structure of the model are delineated in details and the relevant examples of moral imagination in service learning are also discussed. (Contains 1 note.)