Purpose: The purpose of this study isto identify the mediating effects of interpersonal problems in the relationship between Social Network Service (SNS) use tendency and depression among university students. Methods: Data were collected from April 28 to May 7, 2018 and the participants included 222 university students, who responded to the question regarding SNS use tendency, interpersonal problems and depression. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson’s correlation coefficients, and multiple regression using the SPSS/WIN 23.0 program. Results: A positive correlation is found between depression and SNS use tendency (r=.24, p<.001), and among interpersonal problems (r=.62, p<.001), SNS use tendency and interpersonal problems (r=.34, p<.001). Interpersonal problems have a full mediating effect on the relationship between SNS use tendency and depression (Sobel test: 5.24, p<.001). Conclusion: These results suggest that it is important to manage interpersonal problems to prevent depression caused by SNS use tendency.