This study aims at investigating the effects of students' experience of service learning on social ability and cultural competence. Moreover, we also examined the moderating effect of student grade. After analyzing the 1,864 effective questionnaires, the results are as following: First, college students' experience of course-service learning has positive effect on their social ability. Second, college students' experience of service learning (both course and community activity) has significantly positive effect on their cultural competence. Finally, after participation in service learning experience of community activity, social ability and cultural competence of the high-grade undergraduate students outperform those of the low-grade students. Our findings conclude with a discussion of the practical implications for military education.