Learning portfolios have garnered attention in education since the mid-1990s. Despite this, there is a lack of comprehensive research on their effect, particularly regarding their affective factors. This study aims to design a course using learning portfolios in general education and to verify its effects on self-regulated learning, ego-resilience, and self-directed learning readiness. The research involved a total of 226 Korean and Chinese international students from one Korean university. They were surveyed before and after participating in the learning portfolio course. The self-regulated learning abilities, ego-resilience, and self-directed learning readiness of both participating and non-participating groups were measured and analyzed. The findings indicated that learning portfolios significantly enhanced self-regulated learning abilities, ego-resilience, and self-directed learning readiness among Korean undergraduates. Conversely, these activities had no notable impact on the self-regulated learning abilities, ego-resilience, and self-directed learning readiness of Chinese international students. Based on these results, implications were suggested for integrating learning portfolio activities into general education.