Objectives: The purpose of this study was to examine the mediating effects of state anxiety and interpersonal relationship on the relationship between self-forgiveness and happiness of nursing students.Methods: This study used The Korean version of the State Self-forgiveness Scale, State Anxiety Inventory, Relationship Change Scale, and The Oxford Happiness Questionnaire. The data was analyzed by using frequency, percentage, mean, standard deviation, t-test, one-way ANOVA, and Pearson’s correlation coefficient. Baron and Kenny’s method was used to analyze mediating effect between self-forgiveness and happiness.Results: Self-forgiveness, happiness, state anxiety, and interpersonal relationship had correlation with each other. There were the mediating effects of state anxiety and interpersonal relationship on the relationship between self-forgiveness and happiness of respondents.Conclusions: The result showed the mediating effects of state anxiety and interpersonal relationship on the relationship between self-forgiveness and happiness of nursing students. To increase happiness, it is necessary to apply curriculum to reduce state anxiety and improve interpersonal relationship.