The goal of this study is to develop a couple-focused postpartum depression prevention group program for new parents and to examine its effectiveness by comparing the differences between invention group (42 couples) and control group (47 couples) on postpartum depressive symptoms, marital satisfaction, conflict communication patterns, and social support, using longitudinal data. The results show that: (1) couples improved on their understandings of postpartum depression, communication skills, marital quality and preparedness for parenthood, while there were short-term effects on reducing fathers’ prenatal depression and maternal postpartum depression. (2) The prevention program did not show long-term benefits on reducing new parents’ postpartum depression. (3) The dyadic concordance of constructive communication and relational adjustment was significantly higher in the prevention group. The findings support the psychosocial benefits of prevention groups program on improving couples’ communication skills and reducing the risk of postpartum depression, at least for the short-term.