<p>The aim of this study was to examine the bidirectional longitudinal relationship between children’s parental attachment and gratitude. Based on attachment theory, the Paternal Attachment Questionnaire, the Maternal Attachment Questionnaire, and the G6 Gratitude Scale were administered in a three-wave longitudinal survey to 702 children aged 10–11 years from primary schools in Guizhou Province, China, with six-month intervals between each wave. It was found that the effect of paternal attachment on children’s gratitude emerged later, and there was no significant bidirectional relationship between the two. In contrast, maternal attachment not only significantly contributed to the development of gratitude, but also had a significant bidirectional relationship with gratitude. The results suggest that maternal attachment, reflecting the role of mothers as primary emotional caregivers, plays a central role in the development of children’s gratitude, whereas the emotional influence of paternal attachment tends to emerge at a later stage. These findings provide important evidence for understanding how parental attachment differentially contributes to gratitude development, with implications for family-based interventions and culturally grounded parenting guidance.</p>