The purpose of this study was to investigate the effects of children\'s temperament and mother\'s parenting stress on young children\'s social competence. The final goal of this study suggest the fundamental data that can be used in parenting program and counseling. Subjects of this study consisted of 295 mothers who had from four-to five-year-old children drawn from 6 preschools in Cheongju city. Data were analyzed by frequency, percentage, Cronbach α, t-test, F-test, Tukey\'s post hoc test, and Pearson correlation using SPSSWIN Program. The theoretical model was tested by LISREL VIII program. The results of this research were as follows: First, for boys, children\'s activity and adaptability directly influenced on children\'s social competence. Children\'s adaptability and reactivity directly influenced on it for girls. Second, boys\' adaptability directly influenced on mother\'s temperamental and relational parenting stress, and reactivity of temperament directly affected mother\'s temperamental parenting stress. Girls\' temperament such as activity, adaptability, and reactivity directly influenced on mother\'s temperamental parenting stress, and girls\' adaptability and reactivity had a direct effect on mother\'s relational parenting stress. Third, girls\' temperament such as activity, adaptability and reactivity had an indirect effect on mother\'s relational parenting stress through mother\'s temperamental parenting stress while there were no indirect effects for boys. Fourth, girls\' temperament such as activity, adaptability and reactivity had an indirect effect on children\'s social competence through mother\'s temperamental and relational parenting stress while there were no indirect effects for boys. Fifth, mother\'s temperamental parenting stress was not caused for mother\'s relational parenting stress for boys. However, mother\'s temperamental parenting stress directly influenced on relational parenting stress and indirectly affected on children\'s social competence through mother\'s relational parenting stress. Sixth, mother\'s relational stress directly influenced on children\'s social competence, that is, the lower mother\'s relational stress with children, the higher social competence children showed.