Objectives: The aim of this study was to evaluate the relationship between positive and negative effects of participating in self support group, attitudes towards self support group, parenting efficacy, and parenting stress among parents with preschool children by using structural equation modeling.Methods: The participants in this study were parents in Gyeonggido with at least one preschool child who participated in self-support groups. The number of participants was 495. The data were collected using an online survey, and structural equation modeling was employed to investigate significant factors related to parenting stress among parents in self-support groups. IBM SPSS 25.0 and AMOS 21.0 were used in this study to conduct statistical analysis.Results: First, attitudes toward self-support group had no direct effect on parenting efficacy and parenting stress. Second, negative effects of self-support group had a significant direct effect on parenting stress. Parenting efficacy had also a direct effect on parenting stress. Finally, through parenting efficacy, the positive effects of self-support group had both direct and indirect effects on parenting stress. Parents who perceived the self-support group as having a higher level of positive impact reported higher parenting efficacy and they were less likely to experience parenting stress.Conclusion: This study examined the mediation effect of parenting efficacy in relations between related factors of self support group(parents’ attitudes and perceived effects) and parenting stress. Individuals’ perceptions of the positive and negative effects of participating in self-support groups, rather than the circumstances of group activities, are highlighted in this study.