The present study aimed to investigate the influence of demographical variables and parenting stress of mother on their parenting efficacy toward their children who were aged under 36 months. Four hundred and twenty-nine mothers with infants and toddlers completed the questionnaires issued regarding their demographical information. parenting stress, and parenting efficacy. The main results are as follows. First, there were differences in mother's parenting efficacy scores according to the educational level, income level, children’s age, and the parenting stress level of subjects. Second, the interactional effect between the income level and parenting stress on their parenting efficacy determined as a result of this study. Lastly, parenting stress was the most influential factor on parenting efficacy. However, other influential factors on mother’s parenting efficacy were different according to sub-scales of parenting efficacy. These results suggest that parent education for improving mother's parenting efficacy should be provided differently as specific contents of parenting efficacy.