Purpose: The purpose of this study was to determine the impacts of vocational calling, emotional intelligence, and major commitment on nursing college students’ happiness. This study also was conducted to explore major commitment’s mediating effect on the relationship between vocational calling, emotional intelligence, and major commitment among nursing college students. Methods: Participants were 346 nursing college students. Data were collected in November, 2017 with self-report questionnaires and were analyzed using t-test, one-way ANOVA, Pearson’s correlation coefficients, and regression analysis with IBM SPSS 19.0. Results: The regression model explained 33.0% of variance in nursing college students’ happiness (F=41.44, p<.001). Significant factors were emotional intelligence (β=.30, p<.001), grade (β=.20, p<.001), major commitment (β=.18, p=.002), and vocational calling (β=.11, p=.035). Moreover, major commitment showed partial mediating effects on vocational calling and happiness. Major commitment also showed partial mediating effects on emotional intelligence and happiness. Conclusion: The results suggest that nursing college students’ happiness can be increased through strategies aimed at increasing vocational calling, emotional intelligence, and major commitment.