Most studies conducted in the West on the role played by intergenerational families in co-parenting have focused mostly on families with a single mother or those in difficult circumstances, while little is known about the experiences of members of intergenerational intact families during the early postpartum period. This study aimed to explore the intergenerational co-parenting experiences of young parents and grandmothers in China, focusing on how they shared the responsibility of caring for the new mother and infant during the postpartum period. A total of 16 eligible intergenerational intact families, including 16 mothers, 15 fathers and 12 grandmothers, were interviewed. The data set was analysed using the approach of directed content analysis guided by Feinberg's Ecological Model of Co-parenting. The data were categorized into four themes: 'division of labour', 'postpartum and infant care agreement', 'support-undermining' and 'joint family management'. An additional theme, 'expressed a need for family support', emerged from the data on these intergenerational families.The findings emphasize the importance of intergenerational co-parenting relationships in families where two generations co-parent the newborn together.