The purpose of this study is to examine the effect of parental happiness on children's happiness in 4th grade children and to verify the mediating effect of parenting attitudes. As the research subjects, 2,203 elementary school students in 4th grade and their parents were selected as a panel using data from the fourth year of the Korean Child and Youth Panel Survey 2018 conducted by the National Youth Policy Institute. Path analysis was performed using the R statistical package and programs such as Lavaan were used for mediating effect analysis. The findings of the study are as follows. First, parental happiness and children's happiness have a significant direct positive correlation. Second, as a result of examining the effect of parents' happiness on parenting attitudes and children's happiness, warmth, autonomy support, and structure provision among parenting attitudes form a positive correlation with children's happiness whereas inconsistency has a negative correlation with it. Third, as a result of analyzing the mediating effect, not only does parental happiness directly affect children's happiness, but it also shows the path leading to children's happiness through warmth and autonomy support. This study suggests that parental happiness should be preceded in order to increase children's happiness and that when children's choices are respected with a warm and affectionate attitude to improve children's intrinsic motivation, psychological stability and healthy growth and development of children can be achieved. The results of this analysis indicated that parental attitudes of parenting should be checked during the period when their children are in their early puberty, and autonomy to respect their children, affectionate mind, and consistent parenting attitude should be educated.