This paper was to explore the effect of user characteristics of SNS on interpersonal problems of university students. This survey was conducted from March, 2016 to Apeil, 2016 and 315 responses from the survey were used for the analysis. The data was analyzed by descriptive statistics, t-test, ANOVA, Pearson correlation and Multiple Regression. As a main result, limited personal relationship on SNS and SNS utilization time were the significant predictors to interpersonal problems, but SNS access rate, relationships on SNS as well as in real life didn't have the effectiveness to interpersonal problems. In conclusion, to reduce interpersonal problems, limited personal relationship on SNS and SNS utilization time should be controled.