By-integrating-service-learning with curricular planning, universities can provide students with practical opportunities and venues to understand their own emotions and interactions with the older adults. This study aims to investigate the impact of service-learning on university students' perceptions and factors related to interacting with older adults. The participants were students enrolled in an older adult care course at a technological university in central Taiwan, with a total of 193 valid questionnaires collected through convenience sampling and structured questionnaires. The results revealed that the correlation between "feeling happy after interacting with older adults" and "feeling that serving the older adults is very meaningful" was just p>0.01 in the nine aspects of service learning effectiveness, indicating low correlations. Multiple regression analysis found that students' motivation for enrolling in the course accounted for 13.6% of the variation in "feelings after interacting with older adults," while the average score of the service-learning effectiveness questions explained 11.5% of the variation in "I think serving older adults is meaningful". Therefore, the service-learning course has a positive impact on improving the feelings of college students after interacting with older adults.