This study examined the moderating effect of social rejection on the relationship between vulnerability, which is one of the characteristics of pathological narcissism, and depression. Before the main experiment, five preliminary studies were conducted to make a new experimental paradigm, 'first impression effect study with video', to manipulate social rejection and non-rejection. In the main experiment, 152 participants from a university answered a questionnaire about narcissistic vulnerability and were randomly assigned to one of the experimental conditions(social rejection[N=76] and non-rejection[N=76]). The results showed that narcissistic vulnerability predicted depression significantly and positively only in the condition of social rejection. This study has significant implications for the development of an new social rejection experiment procedure by making up for the existing social rejection experiment paradigm, as well as for extending the understanding of the relationship between narcissistic vulnerability and depression considering the role of social rejection. In addition, the findings of this study suggest that people with narcissistic vulnerabilities are more likely to feel depressed in interpersonal situations due to unrealistic expectatioons that require only positive responses from others. Lastly, social and cultural understanding of the psychological maladjustment of pathological narcissism, including narcissistic vulnerability, can be expanded if social and economic status and power of social rejections are considered in this experiment.