The positive predictive effect of children's problem behaviors on parenting stress has been verified to some extent, but research on parents of children with special needs remains insufficient. Moreover, the role of parental personality traits in the relationship between children's problem behaviors and parenting stress, and whether it differs from before the COVID-19 pandemic, remains unclear. Accordingly, in this study, online questionnaires were used to survey parents of children with autism and intellectual disabilities in China - 337 parents before and 604 during the COVID-19 pandemic - to explore the relationship between problem behaviors in the children and parenting stress as well as the moderating effect of parents' personality. The results showed that problem behaviors of children with autism and intellectual disabilities had a positive predictive effect on parenting stress. However, there was no significant difference in this effect before and during the pandemic. In addition, the relationship between children's problem behaviors and parenting stress was moderated by the Agreeableness and Neuroticism of the parents, but only during COVID-19 pandemic. The research results suggest that, during the pandemic when facing problem behaviors of children with autism or intellectual disabilities, positive personality characteristics such as Agreeableness have a protective effect on parenting stress. By contrast, negative personality characteristics such as Neuroticism are risk factors. The study results provide evidence from special groups regarding the role of parents' personalities in the parent - child interaction and the parenting stress models.
