This purpose of this study explored the relationship model among participation attitude, barriers factor and learning effectiveness in service-learning course at four colleges in Southern Taiwan. This data was obtained by questionnaire survey, with 411 effective responses from participants. The results of this study show the participation attitude has a significant positive impact on learning effectiveness in service-learning course. Participation attitude also has a significant negative impact on barriers factor in service-learning course. In addition, barriers factor has a negative effect on learning effectiveness in service-learning course. Furthermore, barriers factor plays a mediating role between participation attitude and learning effectiveness. Finally, based on the results of the research, some suggestions and future study are given.