This study examines the relationship between harsh parenting and child aggression, focusing on the mediating role of child emotion regulation. The research was conducted on a sample of 325 Chinese preschool children and their parents, testing a model that distinguishes between harsh parenting from mothers and fathers. The results show that both harsh parenting from mothers and fathers affects child emotion regulation, which in turn influences child aggression. Specifically, fathers' harsh parenting has a stronger direct effect on child aggression, while mothers' harsh parenting has a stronger effect on child emotion regulation. Additionally, fathers' harsh parenting is more strongly related to sons' aggression than to daughters', whereas mothers' harsh parenting does not show gender differences in its effect on child aggression. The study also discusses the implications of these findings for intervention efforts, family policy, and parenting practices, emphasizing the importance of addressing negative emotions in parenting to prevent adverse effects on children's behavior and emotion regulation.This study examines the relationship between harsh parenting and child aggression, focusing on the mediating role of child emotion regulation. The research was conducted on a sample of 325 Chinese preschool children and their parents, testing a model that distinguishes between harsh parenting from mothers and fathers. The results show that both harsh parenting from mothers and fathers affects child emotion regulation, which in turn influences child aggression. Specifically, fathers' harsh parenting has a stronger direct effect on child aggression, while mothers' harsh parenting has a stronger effect on child emotion regulation. Additionally, fathers' harsh parenting is more strongly related to sons' aggression than to daughters', whereas mothers' harsh parenting does not show gender differences in its effect on child aggression. The study also discusses the implications of these findings for intervention efforts, family policy, and parenting practices, emphasizing the importance of addressing negative emotions in parenting to prevent adverse effects on children's behavior and emotion regulation.