Aim and Background: Recognizing and examining the factors that contribute to the consolidation of marriage and the social institution of the family can be a useful step towards promoting the culture of society. Therefore, the purpose of this study was to investigate the model of marital commitment based on attachment styles mediated by self-differentiation.

Methods and Materials: In a correlational study, among the married students of Islamic Azad University, Science and Research Branch of Tehran in 2017, using the available sampling method, 400 persons (200 women) were selected. They participated in the study, completed the Revised Adult Attachment Scale (RAAS), Differentiation of Self Inventory-Revised (DSIR), and Marital Commitment Questionnaire (MCQ). Data were analyzed through multiple regression in two stages in a, and b paths and c path.

Findings: Results showed that safe and anxiety attachment styles significantly explain the variance of self-differentiation. Also, safe and anxiety attachment styles significantly explain the variance of marital commitment. Finally, self-differentiation can significantly explain the variance of marital commitment. The results show that self-differentiation has mediator role in relationship between safe and anxiety attachment styles with marital commitment.