The purpose of this study is to figure out the meditating effect of interpersonal relationship that takes a part in university life, adult attachment and self-differentiation of Chinese studying in Korea. For this study, 433 Chinese studying in 4-year university located in Busan participated in the data collecting research. The collected data was applied to the model of a structural equation in order to find out the mediating effect from the relationship model between a correlation analysis and a potential variable by using SPSS 21.0 and AMOS 21.0. These are the results from the data analysis and discussion: First, both adult attachment and self-differentiation and interpersonal relationship have a direct effect on university life adjustment. Second, both adult attachment and self-differentiation have a direct influence on interpersonal relationship. Third, there is a partial mediating effect of interpersonal relationship on university life adjustment in the relationship of adult attachment and self differentiation. To make a final conclusion, it is a vital to encourage Chinese students to build a stable adult-attachment in order to appropriately solve problems related in interpersonal relationships and adjust well in university life. It is also essential to help them form the independence and autonomy in order for a right self-differentiation. It is, additionally, required programs and studies for reinforcing the positive supports from others and for improving the level of self-differentiation.