Background: This study aims to analyze the effects of traumatic experience and post-event rumination which are known as occurrence and maintenance factors of social anxiety and verify the mediating effect of self-compassion to the relationship between traumatic experience and post-event rumination. Methods: This study targeted 421 university students as research tools. Social Interaction Anxiety Scale (SIAS), Speech Anxiety Scale (SAS), Traumatic Experience Scale, Post-event Rumination Questionnaire (PRQ) and Korean-version of the Self-Compassion Scale (K-SCS) were used. The study results are as follows. Results: The results showed that social anxiety was high and self-compassion was low when traumatic experience was more frequent and post-event rumination was more frequent. Self-Compassion showed mediating effect in traumatic experience, post-event rumination and social anxiety. It can be interpreted that self-compassion indirectly reduces social anxiety. Conclusions: While existing social anxiety-related studies have been mostly focused on negative cognition, this study explored self-compassion as a positive variable to reduce social anxiety. In conclusion, this study shows the importance of self-compassion promotion, traumatic experience and post-event rumination in therapeutic intervention for people who experience social anxiety. Including this, the study has discussed its limitations and made suggestions.